same here . After starting and closing music app ( spotify , or google's play music ) the music control still appear on the led cover.
Found a way to get rid of it without restarting the phone:
go into setttings , select apps, expand the three dots (top right corner) and select show system apps. Then scroll down and select LED cover service and then select force stop
Note the music control will reappear the next time you start spotify etc, so you will have to repeat the above when you want to remove it
This works wel ....and for me after running Spotify again the music controls won't appear again after closing the case
You must also disable notify's for the music player apps. this is working for Spotify, My Radio, and BNR Radio but not for Samsung Music Player
So work to do for Samsung developers, for example make it possible to disable Music control at all
Having the same problem myself... bored of removing the case every time I listen to music! I don't want to turn off notifications as helps remind me of albums I've pre ordered. Come on Samsung!!!!!
Dude! After closing the cover to avoid waiting just press the power/wake up button once. It will end the animation, controls, touch immediately. At the beggining I had the same concern of your but after trial and error I found out this is the quickest way to get rid of the controls before shoving the phone on the pocket.