Direct answer
For the OnePlus Open, account status, cloud capacity, network, permissions and local storage should be separated before sign-out. First, check sync status and the same recent item on the provider website or another trusted device.
What this covers
- OnePlus Open (CPH2551 and regional variants)
- Foldable device; distinguish cover display, main display and hinge behavior.
- The specific fault this record addresses: photos, contacts, messages or account data will not sync
What it does not cover
- ×The same symptom on a different OnePlus 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
Signed in with a different account than expected
What separates it Data is missing rather than out of date, and the account was recently changed or a second one added. Two accounts on one phone is common and the data lives in one of them.
How to confirm Check exactly which account is signed in and which one the missing data belongs to. This is the most common cause and the easiest to overlook.
- 2
The sync toggle for that specific data type is off
What separates it One category is stale while others are current. Contacts, calendar, photos and notes each have their own switch per account.
How to confirm Check the per-type toggles rather than the account-level one. An account can be signed in and fully connected with contacts sync switched off.
- 3
Cloud storage is full
What separates it Sync stopped on a date and new items never upload, while existing ones are fine. A full cloud account stops accepting new data quietly.
How to confirm Check the cloud storage quota. This is a billing matter rather than a device fault and no phone-side change resolves it.
- 4
Background app refresh or battery optimisation is blocking it
What separates it It syncs when the app is open and never in the background. Sync depends on background work, and power management removes exactly that.
How to confirm Set the app to unrestricted background use and allow background refresh.
- 5
Sync is restricted to Wi-Fi and the phone is on cellular
What separates it Photos upload at home and never elsewhere. This is a deliberate default in several apps.
How to confirm Check the app's network setting for a Wi-Fi-only restriction.
- 6
The item is genuinely still uploading
What separates it Large videos or a big first-time library appear missing on other devices. Upload takes as long as it takes, and the phone shows the item locally throughout.
How to confirm Check the app's own sync status or upload queue rather than judging from another device.
- 7
A password change invalidated the session
What separates it Sync stopped on a date that matches a password change, often with no obvious error. The stored token no longer works.
How to confirm Sign out and back in for that account specifically.
- 8
Two-factor verification is waiting
What separates it Sync is silently stopped and there is a pending verification prompt somewhere, possibly on another device.
How to confirm Look for an outstanding sign-in or security prompt on every device on the account.
- 9
Low power mode deferring background work
What separates it Sync resumes when the phone is charged or plugged in. Low power mode defers exactly this kind of work.
How to confirm Charge above the threshold and compare.
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.
- Exactly which data type is not syncing — photos, contacts, calendar, messages, notes. They are separate services with separate switches.
- Which account that data belongs to, and which accounts are signed in on the phone.
- Whether the data is missing entirely or merely out of date, which are different failures.
- Whether it syncs when the app is open and stops in the background.
- The cloud storage quota and how full it is.
- The date it stopped, and whether a password change, a new device or a plan change happened then.
- Whether any verification prompt is outstanding on any device on the account.
Name the exact data type that is failing
ReversiblePhotos, contacts, calendar, messages and notes sync through separate services with separate toggles and separate schedules. 'Nothing syncs' is almost never true, and naming the one that fails is most of the diagnosis.
Confirm which account is signed in
ReversibleTwo accounts on one phone is ordinary, and the missing data lives in one of them. Data missing entirely rather than merely stale is very often this, and it is the cheapest thing on the list to check.
Check the per-type sync toggle, not the account
ReversibleAn account can be signed in, fully authenticated and working, with contacts sync switched off. The account-level indicator says nothing about the individual data types underneath it.
Check the cloud storage quota
ReversibleA full cloud account stops accepting new data quietly — existing items stay fine and new ones never arrive. It is a billing matter rather than a device fault, and no amount of phone-side troubleshooting resolves it.
Look for an outstanding verification prompt
ReversibleA pending two-factor prompt stops sync silently, and the prompt may be sitting on a different device entirely. Checking every device on the account is worth doing before anything more involved.
Allow background refresh and unrestricted battery use
ReversibleSync depends on the app being allowed to work while you are not looking at it. Data that syncs when the app is open and never otherwise is describing exactly this restriction.
Check for a Wi-Fi-only restriction
ReversibleSeveral apps default to uploading only on Wi-Fi to protect a data allowance. Photos that upload at home and never elsewhere is that setting working as intended rather than a fault.
Read the app's own sync status before concluding
ReversibleLarge videos and first-time library uploads take real time, and the item shows locally throughout. Judging from another device rather than from the upload queue produces a fault report where there is only patience needed.
Sign out and back in for that account only
Signs you outA password change invalidates the stored token and sync stops with no obvious error. Signing out of the single affected account is far cheaper than removing the account entirely, which discards local data on some platforms.
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
- CPH2551 and regional variants. Foldable device; distinguish cover display, main display and hinge behavior.
- Type — book-style FOLDABLE (crease normal)
- OnePlus's book foldable — cover screen plus a large inner folding screen, with a notably subtle crease but still a normal bend line, not a defect. OxygenOS over Android with foldable multitasking (Open Canvas).
- Inner screen care
- Soft-topped inner OLED — no hard styluses, no pressing hard, no forcing objects into the fold. Keep grit out of the hinge; check its IP rating before water.
- SUPERVOOC fast charging
- Fast wired SUPERVOOC charging with the OnePlus charger + cable. eSIM support varies by region.
- Symptom boundary
- This record covers OnePlus OnePlus Open when it photos, contacts, messages or account data will not sync. A different symptom on the same hardware, or this symptom on a different OnePlus 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.
- !Cloud storage is full and the choice is a paid plan or deleting content — that is a decision, not a fault.
- !The account cannot be accessed because two-factor recovery has failed, which is an account-recovery process with the provider.
- !Data exists on one device and not the cloud, and removing the account locally would destroy the only copy — stop and export first.
- !The service itself has an outage, which its own status page will confirm and which nothing on the phone affects.
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. OnePlus Support publishes this as "Support center". Official OnePlus manuals, software, repair and troubleshooting support. What that article does not carry is the model boundary — it is written for a product line, and CPH2551 and regional variants 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
Is the crease normal on my OnePlus Open, and can I use a stylus?+
Yes, a centre crease is normal on any book foldable — the OnePlus Open's is unusually subtle, but the inner screen still bends at the hinge, so a faint crease is expected, not a defect. Do not use a hard stylus or press hard on the soft inner screen, do not remove its factory inner screen protector, and keep debris out of the hinge. A spreading line or lifting screen would indicate damage rather than the normal crease.
My contacts are missing but everything else works.+
Check the per-type sync toggle for contacts, and check which account is signed in. Each data type has its own switch per account, so a fully working account can have contacts switched off — and contacts belonging to a second account is equally common.
Photos upload at home but never when I am out.+
Almost certainly a Wi-Fi-only restriction, which several apps set by default to protect a data allowance. It is working as intended. The setting is in the app's own network or upload preferences.
Sync stopped on a specific date.+
Look at what happened then. A password change invalidates the stored session and stops sync with no obvious error; so does a full cloud account, and so does an unanswered two-factor prompt. All three are silent, and all three are dated.
It syncs when I open the app and never in the background.+
That is background restriction rather than a sync fault. Allow background refresh and set the app to unrestricted battery use — sync depends entirely on the app being allowed to work while you are not looking at it.
My photos are on my phone but not on my other device.+
Check the app's own upload queue rather than judging from the other device. Large videos and a first-time library take real time, and the item shows locally the whole way through — which makes a slow upload look exactly like a failed one.
Should I remove and re-add the account?+
Sign out and back in first — it is the lesser action and it fixes an invalidated session, which is the common cause. Removing an account entirely can discard local data on some platforms, so it belongs after you have confirmed a copy exists elsewhere.
My cloud storage is full. Does that stop everything?+
It stops new data being accepted while existing data stays fine, which is why it presents as sync 'stopping' on a date rather than as an error. It is a billing matter and no phone-side change resolves it.
Messages sync on one device and not another.+
Message sync is frequently the most restricted of all the data types, with its own toggle and sometimes its own device limit. Check that specific setting on both devices rather than the account-level indicator.
How do I know sync is actually working?+
Change one thing deliberately — add a contact, take a photo — and watch for it on the other device. That gives you a known item with a known time, where checking whether an old item is present tells you nothing about whether sync is running now.
Does this answer apply to every OnePlus model?+
No. It is scoped to CPH2551 and regional variants. Foldable device; distinguish cover display, main display and hinge behavior.
What should I record before troubleshooting not syncing or photos or contacts?+
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 not syncing, photos, contacts. The ordered checks preserve that evidence.
When should I stop and use qualified service?+
Never sign out or delete originals until another verified copy exists.
Answer for the exact device and software version shown above.