If you're having issues with the Luminary player in Notifications disappearing when you pause, or not being able to resume playback from your bluetooth devices, please check the below settings:
Go to System Settings > Device Management > Battery > Unmonitored apps > Add Luminary
This should tell your phone that Luminary is a media app and it should not immediately stop it from running in the background.
Still having issues? Go to the Luminary app > Settings > Report an Issue and let us know! If you're unable to do this, you can also email us at firstname.lastname@example.org