Problem with Android process manager

Here we are talking about completely different things. In Android almost everything related to UI is placed in Activity.

Activities are one of the fundamental building blocks of apps on the Android platform. They serve as the entry point for a user's interaction with an app, and are also central to how a user navigates within an app (as with the Back button) or between apps (as with the Recents button).

When user minimizes the app, the Activity goes into pause state. This does not means system has destroyed the process of app, everything in kept into place and when maximizing the app everything will work correctly. However system may destroy Activity in extreme low memory conditions.


So, what is happening in case of YouTube?

When user minimizes the app, YouTube app pauses the playback and this is performed intentionally and there is nothing wrong with Process Manager.

Can we play YouTube in background?

Yes. There is an Xposed Module called YouTube Background Playback, which requires Xposed Framework installed, of course.

Further, YouTube developers can design the app in such a manner that playback does not pauses when app is minimized, like other music apps does. They can use a Service for playback, which can run in background even if app is minimized.