Android Question Tracker example doesn't run when user puts device into sleep

Tested on a Xiaomi Mi9 pro then this doesn't occur (android 10)
Tested on a CAT then this doesn't occur (android 4)
Tested on a Samsung Galaxy A9 then this does occur (android 9)

then i ran out of phones

Tracker = https://www.b4x.com/android/forum/t...-run-when-user-puts-device-into-sleep.124729/
The activity is not related to the service.

The service acquires a partial lock. It should keep running in the background. You can add a timer to check it.
It is possible that the device turns off the GPS, though it will break other navigation apps as well.

I've tested it with a clean download of:

The timer keeps coming back in de logging but the GPS_LocationChanged isn't being triggered any more after using the power button to set the screen dark. This is on a Samsung Galaxy A8. What I also noticed is that, when the screen is dark the GPS_LocationChanged isn't triggered. But when pressing the powerbutton, and you can see the lock-screen, then it is getting triggered.

The same application on a Xiaomi Mi9 works like a charm.

Two things that might help a bit:
1. Whitelist your app in the device settings. On some devices there are such options.
2. Turn the screen on with PhoneWakeState every X seconds and keep it on.