Activity is randomly shown, what's the problem?

Question

Android

On some devices, the main Activity from the application pops up. Some complain that it is shown when turning, others cannot bind to something at all. I can't repeat it on my devices. What could be the problem? Where should you go?
Also in the application there is a permanent notification for the foreground service.
SOLUTION FOUND!

Answer 1

Where should you go?

obviously in methods that explicitly or implicitly call activities