How to enable notifications on Samsung smartphones with Android Version 9 or 10?

Modified on Wed, 27 Jul 2022 at 05:47 PM

Battery optimizations are turned on by default. It is possible the disabled restrictions might get revert after OS update or reboot:
Settings > Device Care > Battery > App power management
Disable Put unused apps to sleep
Remove your app from the list of Sleeping apps - list of apps not allowed to run on the background
Remove your app from the list of Deep sleeping apps - list of apps that can only work when you open them
Add your app to the list of Apps that won’t be put to sleep
Disable Auto-optimization
Warning: Make sure Put unused apps to sleep is disabled. Otherwise, Samsung will put your apps back to sleep after a few days (3 by default) even if you have woken them up manually!