On leaving media player, media does not stop playing in iOS app

Context

• iPhone 7 Plus

• iOS 14.4.2 (18D70)

• Media types tested

  • mp4
  • wav

Steps to reproduce

• Open a media item from nextcloud iOS app
• After the media starts streaming in-app, tap the streaming window to start playing in the (presumably?) native player
• After media begins streaming in the second player, immediately exit using the exit icon
• Before the media starts to play in-app again, leave the streaming window with the back icon
• The audio of the media will continue playing in the background
• If you enter back into the media, or any other media file, the media will stream at the same time as the background stream
• You can see the active media window in the control center. But pausing this will not stop the media, and pressing play will start a second stream
• The only way to stop the media is to manually stop the app. In my case, I double-tap home button and swipe the Nextcloud window off

To Note

• On exiting the native player, if the in-app stream is given a chance to begin, the media will stop when tapping back; as expected
  • It's only when exiting 'early' that the media seems to load an unstoppable stream in the background
• I believe there are other sequences through which this issue can arise, but the above is the only way I can consistently reproduce the issue
• Log file does not seem to report any errors or warnings over the period of the issue

Reproduce the issue on the listed iPhone and iOS version using the described native-player exit sequence. Start by tracing the iOS app's media streaming and player-exit lifecycle; no source files or tests are named. Done means leaving the player stops the stream, and reopening media does not create overlapping playback.