Fix notification delay on Android

What causes the notification delay error?

Notification delay error on Android occurs when the system cannot send notifications to your device immediately when a new event occurs on the application. Typically, on Facebook, Zalo, Telegram, etc., notifications may be delayed or not appear until you open that app.

I also have an extremely annoying case when sms messages are also delayed until the screen is unlocked.

There are many causes of notification delay on Android, including:

• Turn off app notifications.
• The application is blocked from running in the background.
• Problems with wifi, 4g, 5g networks.
• Device overloaded: When your device is overloaded, the system may suspend some activities including notifications to reduce the load on the device.
• “DOZE” mode does not work properly.

How to fix the error of notification delay

Check application configuration

During use, you accidentally made a mistake on the notification bar because you clicked the "Turn off notifications for this application" button. This causes the application to be completely blocked and no longer delay notifications.

To fix this error, follow these steps:

1. Open the settings on your phone.
2. Find and select “Applications” or “Application Manager” (name may vary depending on Android version and device interface). A faster way is to hold and select the application icon on the desktop → Application information.
3. Select the "Notifications" section.
4. Check the notification items. Depending on your needs, turn it on / off, not necessarily open it all.

Allow apps to run in the background

This can be seen as a feature, not a bug. There are apps that force you to allow background activities, especially apps that listen to music and audio when the screen is off.

Usually these applications will popup a notification to allow background activity right from the time of installation. If not, you can do it manually like below:

1. Follow the first 2 steps as instructed above to get to the "Application information" section.
2. Select “Permissions” or “Apps running in background”.
3. Turn on “Allow background activities” or “Allow apps to run in the background”.

Note that allowing an app to run in the background can affect performance and battery life.

Optimized in battery saver

"Battery experts" usually turn on all options related to battery optimization. This accidentally causes some applications to delay notifications.

1. Open your phone's battery settings.
2. There will be sections on optimization, super battery saving.
3. You should only enable the “Optimize battery performance” (Adaptive Battery) options. As for Battery Saver, turn it off (you should only use this feature when the % battery is too low and you want to extend usage time in special cases).

When the Adaptive Battery feature is enabled, the system learns to use and optimize battery usage by minimizing unnecessary application activity.

For example, if you usually use Facebook in the morning, but don't use it in the evening, Adaptive Battery will minimize Facebook activity in the evening to save battery.

Keep wifi, 4g, 5g always working

By default, the network will always work even when the screen is off. The purpose is for applications such as Facebook, Zalo, and banking applications to promptly notify.

To check these options follow these steps:

1. Go to Wifi option find advanced item.
2. Turn off the "Turn off Wi-Fi automatically" option.
3. Similar to Wifi, 4g and 5g network data can also be turned off automatically or reach the bandwidth limit for the day. You need to increase your mobile data limit to stay informed.

Turn off “DOZE” mode

“DOZE” mode is a hibernation mode introduced on Android Marshmallow (6.0). When in Doze mode (inactive and screen turned off), the Android system reduces data sync frequency, limits network connections or app updates, and only allows priority notifications. description is displayed.

When the device is screen unlocked, the system will reactivate the full operation of applications and hardware.

This feature increases battery life and reduces battery consumption significantly when the device is not in use. However, for those of you using local ROMs, or custom ROMs, there is still the possibility that this feature does not work properly and causes the application to turn off notifications when Off Screen.

You can follow the steps below to disable the Doze mode feature on your Android device.

Turn off with ADB command:

1. adb shell dumpsys deviceidle disable This command to turn off Doze mode.
2. adb shell dumpsys deviceidle enable This command to enable Doze mode.

Or you can add specific apps to the white list with this command (in my case, sms notification was delayed so I added app com.android.messaging)
adb shell dumpsys deviceidle whitelist +com.android.messaging

If you "shutdown / start up” computer again, you must run this command again.

In case you do not have a computer, you can use “Terminal Emulator” in Play Store to run ADB directly on your phone through “Wireless debugging”.