I've noticed that sometimes when i'm using Spotify, the notification that shows which music is being played disapears from the status bar. I no longer get the status of the app and the controls from the lock screen are missing too. This usualy happens if i've previously connected my phone to my car's bluetooth, which is setted to launch Spotify uppon pairing. This might be due to the way the app is launched because when i force close it and open it again from the drawer, it works as expected.
OxygenOS 5.0.3 (Android 8.0.0)