In the vast majority of cases the culprit is battery optimisation: Android puts the app to sleep in the background and messages only show up once you open it. Start with Solution 1, which marks the app as Unrestricted or Not optimised. If alerts keep going missing, check the app's notification permission (Solution 2) and whether Do Not Disturb or a focus mode got switched on by accident (Solution 3). When only one app is affected, its own internal setting is usually off (Solution 4). When every app is affected at once, go to Solution 6 onward.
What causes this problem
- Android battery optimisation restricting the app in the background - by far the most common cause, especially on phones with aggressive power saving.
- The app's notification permission switched off, or just one alert channel disabled inside it.
- Do Not Disturb, a focus mode or an automatic routine silencing everything at certain hours.
- The notification setting inside the app itself turned off, independently of the system.
- Background data restriction or Data Saver cutting the connection the app uses to receive alerts.
- A temporary glitch in the Google messaging service on the device, which clears up by wiping the app cache or restarting the phone.
- Work out whether the problem hits one app or all of them. If it is one, jump to Solutions 1, 2 and 4. If it is all of them, Do Not Disturb and the general sound settings are the likelier path.
- Check the basics: notification volume is not muted and the phone is not on silent or vibrate.
- Test by sending yourself a message through the app in question, with the screen locked, to see whether the alert arrives.
- Note the make and model of your phone: menu names vary a lot between manufacturers, even on the same Android version.
- Give it a few minutes without touching the phone after each change - some settings only take effect when the app receives its next message.
Solutions, in the order to try them
1Take the app out of battery optimisation
This is the first place to look and it fixes most cases. To save power, Android suspends apps that spend a long time off screen, and the connection that carries notifications drops with them. Marking the app as unrestricted gives it back the right to run in the background. It costs a little more battery, so do this only for the apps that genuinely need to reach you right away.
- Press and hold the app icon on the home screen and tap the app info shortcut (usually an 'i' in a circle).
- Look for the battery or battery usage section.
- Choose Unrestricted, No restrictions or Not optimised, whichever wording your phone uses.
- Repeat for every app that needs to alert you in real time: messengers, email, banking, calendar.
- On phones with a manufacturer's own skin, also look for a protected apps or auto-launch list and add the app to it.
2Review the app's notification permission
On recent Android versions every app has to ask permission to notify you, and plenty of people tap Don't allow without thinking the first time they open it. Beyond the main switch, each app splits its alerts into categories - it is common for the app to be allowed while the exact category you want is off.
- Open Settings > Notifications > App notifications (some phones call the section Apps and notifications).
- Find the app in the list and confirm the main switch is on.
- Open the app entry and go through the alert categories one by one, enabling the ones you care about.
- Inside each category, check the behaviour is set to Default or High priority rather than Silent.
- Also check that showing on the lock screen is enabled, if that is where you normally notice alerts.
3Check Do Not Disturb, focus mode and automatic routines
Do Not Disturb silences everything without giving a clear sign that it is on, and it is easy to switch on by accident from the quick settings panel. Worse, it can be scheduled to turn itself on at certain hours, during sleep, or when the phone connects to a particular device. If notifications always vanish at the same time of day, the cause is almost certainly here.
- Pull down the quick settings panel and check whether the Do Not Disturb icon (usually a crossed circle or a moon) is lit.
- Open Settings > Notifications > Do Not Disturb and look at the active schedules.
- Turn off any automatic schedule you do not recognise.
- Also look for focus modes or digital wellbeing and check whether an app was paused there.
- If you use a connected watch, check it is not set to silence the phone while it is on your wrist.
4Check the alert settings inside the app itself
Messaging, email and social apps have their own notification controls, separate from the system. A single conversation may be muted, or alerts may be on for mentions only. If one app is affected and everything else works, look here before touching any system setting.
- Open the app and go into its settings, usually behind a gear icon or your avatar.
- Go to the notifications section and confirm alerts are on for the kind of content you expect.
- In messengers, open the specific conversation and check it is not muted individually.
- Check the right account is signed in: in apps with several accounts, alerts may be on for only one of them.
5Force stop the app and clear its cache
When an app was working and stopped out of nowhere, it is often its background process that got stuck. Force stopping and clearing the cache tears down that stuck state and makes the app register its notification connection again. The cache holds only temporary files, so nothing you wrote or saved is lost.
- Press and hold the app icon and open the app info screen.
- Tap Force stop and confirm.
- Go into Storage and choose Clear cache. Do not touch Clear data at this stage, because that signs you out.
- Open the app again, let it load your messages and test.
6Allow background data and turn off Data Saver
Alerts arrive over a connection the app keeps open even when closed. If Data Saver or an individual restriction blocks that traffic, messages pile up and only appear once you open the app on Wi-Fi. That is the usual explanation for anyone who only gets notifications at home.
- Open the app info screen and go into Mobile data and Wi-Fi (the name varies between phones).
- Turn on background data usage.
- Also turn on unrestricted data usage, which frees the app even with Data Saver enabled.
- In Settings > Network and Internet, check that Data Saver is off or that the app is on the exception list.
7Turn off automatic pausing of unused apps
Android strips permissions from and puts to sleep apps you go weeks without opening. Anyone who only uses an app occasionally finds it stopped alerting for exactly this reason. Turning that pause off for the apps that matter stops the problem from coming back on its own later.
- Open the app info screen.
- Look for the option to pause app activity if unused, or to remove permissions and free up space.
- Turn that option off for the apps that need to reach you.
- While you are there, confirm the notification permission stayed on after the change.
8Update the app, update the system, reinstall if needed
If nothing above worked, what is left is an outdated app or a damaged installation. Updating first is the safe route. Reinstalling should come afterwards, and carefully: messaging apps can lose their history without a backup, and banking apps usually require a fresh device authorisation.
- Open the app store, find the app and install the update if there is one.
- Go to Settings > System > Software update and install anything pending.
- Restart the phone and test before anything more drastic.
- If it still fails, back up the app, uninstall it and install it again from the official store.
- As a last resort, use the reset app preferences option in system settings: it re-enables disabled services without deleting your files.
Applies to
| System | Status |
|---|---|
| Android 13 or newer | Confirmed |
| Android 10 to 12 | Confirmed |
| Manufacturer skins (Samsung, Xiaomi, Motorola and others) | The steps are the same, but menu names differ and there are extra protected-app lists |
Menu names can change slightly between versions. If a step above does not match what you see on screen, the official support page from the manufacturer has the most current wording for your version.
Frequently asked questions
Last checked: Oct 23, 2026 · We review this guide whenever the manufacturer changes the process.