Do you experience these symptoms if you test your device in safe mode?
-If your phone is misbehaving, it's possible that a third-party app is causing the issue. To figure out what app is acting funny, you can use the Safe Mode feature. In Safe Mode, your phone won't run any third-party apps. This allows you to easily identity and remove the app that may be causing the problem.
Give this link a try to test your device in safe mode:
Thank you for that information. After further research, this appears to be a feature after the update to Android 10.
Can I have a source regarding that? - a changelog or something similar?
because it doesn't really look like a "feature" to me as pressing power button every time I'm in a call to look at something is a very annoying thing to do.