Slow response on a phone or tablet is almost always storage near capacity or a background sync, not processor failure. For Android notification channels, first open the notification history/channel from a missed alert and send an in-app test.
What this covers
- Android notification channels with this exact failure state
- Diagnosis across app-wide permission versus one disabled channel, Focus and battery restriction
What it does not cover
Try in this order
0 of 4 completedCapture the exact failure state
ReversibleCheck available storage, and whether a backup, update or large download is running in the background. Expected behavior: deliver each alert category with the selected sound, visibility and priority.
Isolate the component boundary
ReversibleOpen the notification history/channel from a missed alert and send an in-app test. Compare the delay in a nearly-empty app versus the affected one, with background app refresh paused. Boundary to separate: app-wide permission versus one disabled channel, Focus and battery restriction.
Correct only the proven cause
ReversibleEnable only the needed channel and allow appropriate background activity. Free storage, let the background task finish, or clear the one app's cache/data where the OS supports it.
Verify and stop safely
ReversibleRepeat the same timed action twice with no background task running. Preserve emergency and security alerts; do not disable all battery protection.
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