Direct answer
For the Samsung Galaxy S25, app permission, channel/category, Focus modes, background restriction, account sync and network should be separated. First, send a controlled test while the app is open, then locked.
What this covers
- Samsung Galaxy S25 (SM-S931*)
- Samsung Galaxy family; S Pen, foldable display, DeX, USB moisture and One UI features vary by exact model.
- The specific fault this record addresses: notifications are delayed or missing
What it does not cover
- ×The same symptom on a different Samsung product line, which has its own record and its own cited source
- ×An on-screen error code whose meaning has not been checked against this exact model's manual
- ×Live electrical, gas, sealed-system, internal battery-cell or structural repair — a technician boundary, not a self-service step
Differential
What actually causes this, and how to tell them apart
These are ordered by how often each one is the answer, not by how easy it is to try. The point of the middle column is that two causes producing the same headline symptom rarely produce the same detail — that detail is what tells you which one you have before you change anything.
- 1
A focus mode or scheduled summary is holding them
What separates it Notifications appear later, in a batch, or not until the phone is unlocked. Focus modes, bedtime schedules and scheduled summaries all do this deliberately and quietly.
How to confirm Check for an active focus mode and any scheduled summary. This is the most common cause and it is invisible from the notification itself.
- 2
Battery optimisation is restricting the app
What separates it One app is late while others are prompt, on Android in particular. Aggressive per-app power management stops background work, and notification delivery depends on it.
How to confirm Set that app to unrestricted battery use. This is the single highest-hit-rate action on Android for this symptom.
- 3
Notification permission was never granted or was revoked
What separates it Nothing at all from one app, ever. Both platforms now require explicit permission and it is easy to dismiss the prompt at install time.
How to confirm Check the app's notification permission specifically rather than its in-app settings.
- 4
The app's own settings are off
What separates it The system permission is granted and still nothing arrives. Apps carry their own notification preferences, often per category and per account.
How to confirm Check inside the app as well as in system settings. Both have to agree, and each is capable of silencing the other.
- 5
The event never happened
What separates it Nothing appears in the app's own history either. A notification cannot be missing for something that was never generated.
How to confirm Open the app and look for the item. Present in-app but not notified is a delivery problem; absent in-app is not a notification problem at all.
- 6
Notifications are silent rather than missing
What separates it They are in the shade but made no sound and showed no banner. Delivery style is configurable per app — silent delivery is a real setting.
How to confirm Check the app's alert style for banner, sound and lock-screen settings separately.
- 7
The phone is on a network that blocks push
What separates it Notifications stop on one specific Wi-Fi network and resume on cellular. Restrictive workplace and guest networks block the ports push services use.
How to confirm Compare the same app on Wi-Fi and on cellular data in the same place.
- 8
Signed out of the account, or signed in on another device
What separates it Notifications stopped after signing in elsewhere. Some services deliver to the most recent device only.
How to confirm Check the account status inside the app rather than assuming the session persisted.
- 9
Do Not Disturb during a schedule nobody set deliberately
What separates it Notifications are silent at consistent times of day. Bedtime schedules and driving focus both activate automatically.
How to confirm Look at the focus schedule rather than the notification settings.
Before you touch a setting
Record this first — changing settings destroys the evidence
Every item below stops existing the moment a reset, re-pair or settings change is made. Written down first, they are what separates the causes above; recovered afterwards, they are guesswork.
- Whether the item exists in the app's own history — this splits a delivery problem from an event that never happened, and costs one look.
- Whether it affects one app or all of them.
- Whether notifications are absent, late, or present but silent. Those are three different failures.
- Whether the problem follows a time of day, which points at a schedule rather than a setting.
- Whether it happens on Wi-Fi, on cellular, or both.
- The app's system notification permission, and separately its in-app notification settings.
- The app's battery optimisation state.
Check whether the item exists in the app itself
ReversiblePresent in the app but never notified is a delivery problem. Absent from the app entirely is not a notification problem at all, and no notification setting will produce an alert for something that was never generated. One look, and it halves the work.
Check for an active focus mode or scheduled summary
ReversibleFocus modes, bedtime schedules and scheduled summaries hold notifications deliberately and give no indication in the notification itself. This is the most common cause, and a problem that follows a time of day is almost always this.
Separate absent from late from silent
ReversibleAbsent points at permissions or the app. Late points at background restriction or the network. Silent points at the delivery style setting. Three different failures that get reported with the same words.
Set the app to unrestricted battery use
ReversibleAggressive per-app power management stops the background work that notification delivery depends on, and it is applied automatically to apps the phone thinks you use rarely. On Android this is the single highest-hit-rate action for late notifications.
Check the system permission and the in-app settings separately
ReversibleBoth have to agree and each can silence the other independently. An app with system permission granted and its own category switched off delivers nothing, and looking at only one of the two explains nothing.
Compare Wi-Fi against cellular in the same place
ReversibleRestrictive workplace and guest networks block the ports push services use, which stops notifications on that network only. Testing both takes a minute and identifies a cause no phone setting would reveal.
Confirm you are still signed in
ReversibleSome services deliver to the most recent device only, so signing in elsewhere silently stops delivery here. Check the account inside the app rather than assuming the session persisted.
Test with the phone locked
ReversibleNotification behaviour differs between an unlocked phone in your hand and a locked one in a pocket, and only the second reflects real use. A fix confirmed with the phone unlocked and awake has tested the easiest case.
Reinstall only after the settings are excluded
Signs you outA reinstall clears the app's own preferences and re-prompts for permission, which is why it sometimes works — but it teaches you nothing about which layer failed, and the same cause will take out the next app.
Model-specific
What is true of this model and not of its siblings
Generic advice for the product line fails here. Each item below is a property of this specific model family that changes which of the steps above apply to you.
- Model scope
- SM-S931*. Samsung Galaxy family; S Pen, foldable display, DeX, USB moisture and One UI features vary by exact model.
- Display
- 156.4mm (6.2" full rectangle) / 152.3mm (6.0" rounded corners), 2340 x 1080 (FHD+), Dynamic AMOLED 2X, up to 120 Hz. Samsung quotes two figures for screen size — the full rectangle and the rounded-corner measurement — which is why this phone is listed at two different sizes in different places and neither is wrong.
- Refresh rate
- Up to 120 Hz adaptive. A high refresh rate is one of the larger discretionary battery costs on this phone: it is genuinely smoother and it genuinely costs runtime, which is why battery complaints on this model are worth checking against the refresh-rate setting before anything else.
- Panel
- Dynamic AMOLED 2X. This is an AMOLED panel, so dark mode reduces consumption for real — black pixels are switched off rather than backlit — and a static bright element left on screen for very long periods is the one wear risk this panel type has.
- Rear cameras
- 50.0 MP + 10.0 MP + 12.0 MP. The main sensor is 50 megapixels, which produces substantially larger files than a 12-megapixel camera and is a meaningful contributor to how quickly storage fills.
- Zoom
- Optical Zoom 3x, Optical quality Zoom 2x (Enabled by Adaptive Pixel sensor). Zoom range is the practical difference between models in this line. A close-up that will not focus at the long end is normally the telephoto's minimum focus distance rather than a fault — taking the same shot at 1x confirms it in seconds.
- Video
- UHD 8K (7680 x 4320)@30fps. Resolution and frame rate dominate how quickly video fills storage and how hard the phone works thermally — sustained 8K recording is the single most common reason a Galaxy camera stops mid-take and warns about temperature.
- Memory and storage
- 12GB RAM with a 128GB storage tier. RAM matters directly to one symptom: apps reloading when you switch back to them is memory pressure rather than a crash, and it is more likely on the lower-RAM configurations.
- SIM
- SIM 1 + SIM 2 / SIM 1 + eSIM / Dual eSIM. Three combinations are supported, and the default line for calls, for messages and for cellular data are three separate settings — crossing them produces calls arriving on one number while data or messages use another, with almost no indication that anything is wrong.
- Wi-Fi
- 802.11a/b/g/n/ac/ax/be 2.4GHz+5GHz+6GHz, EHT320, MIMO, 4096-QAM. This is Wi-Fi 7 hardware with 6 GHz support, so it can use bands an older phone on the same network cannot — which is worth knowing before concluding the router is at fault when one device performs differently from another.
- Bluetooth
- Bluetooth v5.4. Version affects range, reconnection behaviour and which accessory features are available — a newer accessory paired here operates at this version's capabilities rather than failing, which is regularly mistaken for a pairing fault.
- Connector
- USB Type-C. Note that a USB-C cable which fits is not necessarily rated for this phone's charging speed: USB-C carries several power profiles, and a data-oriented cable charges slowly or intermittently while seating perfectly.
- Processor
- 4.47GHz, 3.5GHz octa-core. Clock speed is not the useful number for troubleshooting; what matters is that sustained heavy work throttles, so performance measured while the phone is already hot is measuring the throttling rather than the phone.
- Samsung's own specification
- Samsung publishes the full specification for this model at samsung.com/uk/smartphones/galaxy-s25/specs/. Where any figure above matters to a decision, that page is the authority and this one is not.
- Biometric
- An in-display fingerprint reader, which looks through the screen. A thick or incompatible screen protector genuinely interferes with it, which is why unlock reliability often changes the day a protector is fitted rather than gradually.
- Modem
- 5G capable. In marginal 5G coverage the phone hands repeatedly between 5G and LTE, which costs more battery and generates more heat than settling on either — so the preferred-network setting is a real diagnostic lever rather than a preference.
- Charging
- Supports wireless charging. Coil alignment is tighter than it looks and a thick case, a metal plate or a card in the case defeats it entirely — so wireless charging failing while cable charging works is usually the case rather than the phone.
- Water resistance
- Rated water resistant, which is not waterproof and which degrades with age, drops and seal disturbance. The rating covers incidental exposure; it is not a guarantee, and moisture-detection warnings are deliberately conservative and can persist after the port feels dry.
- Platform
- Android, with a manufacturer interface layer over it. Battery optimisation and background-execution restrictions are applied per app and are far more aggressive than on iOS — which is why 'set this app to unrestricted' is a real fix here and has no equivalent elsewhere.
- Symptom boundary
- This record covers Samsung Galaxy S25 when it notifications are delayed or missing. A different symptom on the same hardware, or this symptom on a different Samsung product line, has its own record with its own causes and its own cited source.
Stop boundary
When this stops being a self-service repair
Continuing past any one of these costs more than the repair saves — in safety, in warranty, or in evidence a technician needs.
- !Notifications fail across every app after every setting has been checked, which points at the system rather than any app.
- !The service itself is failing to send — the app's own status page or support is the path, not the phone.
- !The phone is on a managed network where push is blocked by policy and only an administrator can change it.
- !Notifications are being relied on for anything safety-critical, which no consumer push service is specified for.
Evidence ledger
Sources behind this answer
Visible sources support the visible claims. Home Product Support records the publisher, the fact used and the review date; community reports can suggest an issue but do not become a published fact on their own.
Where the manufacturer's article stops. Samsung publishes this as "Apps on Samsung phone or tablet are not sending notifications". Covers missing or delayed app notifications on a Galaxy phone - notification permissions, battery optimization and sleeping apps. Probed 2026-08-21: title-verified. What that article does not carry is the model boundary — it is written for a product line, and SM-S931* is the scope applied here. Where a control label, terminal, indicator pattern or reset sequence differs on your unit, the manual for that exact model is the authority, not this page and not the article.
Exact questions
Common follow-ups
What size is the Galaxy S25 screen?+
Samsung lists 156.4mm (6.2" full rectangle) / 152.3mm (6.0" rounded corners), at 2340 x 1080 (FHD+). The two size figures are the full rectangle and the rounded-corner measurement — both are Samsung's own numbers, which is why this phone appears at two different sizes in different places.
Does the Galaxy S25 have a 120Hz screen?+
Yes, up to 120 Hz adaptive on a Dynamic AMOLED 2X panel. It is worth knowing for battery complaints specifically: a high refresh rate is one of the larger discretionary costs on this phone, and it is the first setting to check when runtime is disappointing.
Does dark mode save battery on the Galaxy S25?+
Yes, genuinely — it uses an Dynamic AMOLED 2X panel, where black pixels are switched off rather than backlit. The saving is real though smaller than reducing brightness or refresh rate, which remain the larger levers.
What cameras does the Galaxy S25 have?+
50.0 MP + 10.0 MP + 12.0 MP, with optical zoom 3x, optical quality zoom 2x (enabled by adaptive pixel sensor).
How much storage and RAM does the Galaxy S25 have?+
12GB RAM and a 128GB storage tier. The RAM figure is the one that matters for a specific symptom: apps reloading from scratch when you switch back to them is memory pressure rather than crashing, and it is more likely on lower-RAM configurations.
Does the Galaxy S25 support eSIM?+
Yes — Samsung lists SIM 1 + SIM 2 / SIM 1 + eSIM / Dual eSIM. Because more than one line can be active, check which line is set as the default for calls, for messages and for cellular data separately; those are three settings and crossing them is easy to do and hard to notice.
What Wi-Fi does the Galaxy S25 support?+
802.11a/b/g/n/ac/ax/be 2.4GHz+5GHz+6GHz, EHT320, MIMO, 4096-QAM. That is Wi-Fi 7 with 6 GHz, so it can use bands an older phone on the same network cannot — a useful thing to know before blaming the router when two devices behave differently.
Can the Galaxy S25 record 8K video?+
Yes — UHD 8K (7680 x 4320)@30fps. Bear in mind that resolution and frame rate dominate both how fast storage fills and how hard the phone works thermally, and sustained 8K is the most common reason a Galaxy camera stops mid-recording with a temperature warning.
What Bluetooth version is the Galaxy S25?+
Bluetooth v5.4. Version affects range, reconnection and which accessory features are available — a newer accessory paired here runs at this version's capabilities rather than failing, which regularly gets misread as a pairing fault.
My notifications arrive hours late.+
On Android this is usually battery optimisation restricting the app in the background, and setting that app to unrestricted use is the highest-hit-rate fix. On either platform, check for a scheduled summary or a focus mode — both hold notifications deliberately and neither says so.
I get nothing at all from one app.+
Check the system notification permission first, then the app's own settings. Both have to agree, and each can silence the other independently — an app with permission granted and its own category switched off delivers nothing at all.
How do I tell whether the notification was even sent?+
Open the app and look for the item in its own history. Present in the app but never notified is a delivery problem worth chasing. Absent from the app entirely means nothing was generated, and no notification setting can conjure an alert for it.
Notifications are silent but they are in the shade.+
That is a delivery-style setting rather than a failure. Banner, sound and lock-screen presentation are configurable per app, and silent delivery is a real option that gets applied without much ceremony. Check the alert style for that app.
They stopped working after a system update.+
Updates commonly reset per-app notification permissions and background activity allowances. Check both for the affected apps specifically — this is one of the most predictable side effects of a major update and it looks exactly like an app fault.
It only happens at work.+
Compare the same app on Wi-Fi against cellular data in the same place. Restrictive workplace and guest networks block the ports push services use, which stops delivery on that network only — and no phone setting would ever reveal it.
Should I reinstall the app?+
Only after the settings are excluded. A reinstall clears the app's preferences and re-prompts for permission, which is why it sometimes appears to work — but you learn nothing about which layer failed, and the same cause will take out the next app you install.
Notifications are quiet at the same time every evening.+
Look at focus schedules rather than notification settings. Bedtime and driving focus modes activate automatically on a schedule, and a problem that tracks a time of day is almost always one of them.
They work when I am using the phone but not otherwise.+
That is background restriction. Delivery depends on the app being allowed to do work while you are not looking at it, and power management removes exactly that. Set the app to unrestricted and test with the phone locked and in a pocket.
Does this answer apply to every Samsung model?+
No. It is scoped to SM-S931*. Samsung Galaxy family; S Pen, foldable display, DeX, USB moisture and One UI features vary by exact model.
What should I record before troubleshooting notifications or delayed alerts?+
Record the complete model identifier, exact message or indicator, software/firmware where visible, the operating stage and what still works.
Why is a factory reset not the first step?+
A reset can erase accounts, networks, maps, schedules or preferences without distinguishing notifications, delayed alerts. The ordered checks preserve that evidence.
When should I stop and use qualified service?+
Preserve emergency, security and authentication alerts.
Answer for the exact device and software version shown above.