Nokia 7.2 Display Does not Turn Off


I searched this forum and internet but couldn't find a solution.

In recent months, my phone has started not to turn off the display. It is set to 15 seconds. If I restart, it turns off for a while, but some time later (a couple of hours maybe) the display stops turning off. I have seen similar problems in other brands on the web, some with solutions that did not work for me, and others without any solutions. I am guessing that some program(s) in the background are preventing the phone from turning off the display.

I have tried using "Developer Options/Running Services" but it does not show any app I have installed working in the background. In the past there used to be an app showing the programs working in the background (Wakelock Detector) but it is not supported in Android 10, or I couldn't make it work.

Any suggestions? All help are appreciated. Thank you.