Question about the application in the background?

Question

Android

1. I noticed a bug in my application that occurs when the application has not been opened for a long time and in the recentapps list it has become black (and not a picture), I click on it, as I understand it is no longer onResume but a new launch, but somehow it does not start up like that like the first time you started. is there any difference? how do I manually send the application to this state for the test, so as not to wait half a day for system
2 to do this. in addition, the application has a service launched by Activity.onStart, the idea is that it should always work, but if I remove the app through recentapps, then the service also ends

Answer 1

1. Do not keep activities in developer options
2. Google START_STICKY and startForeground