[BUG] Missing music control apps

[karbolak]

Hi!
I use Smart Audiobook Player for listening to my audiobooks. It is never automacially marked as a music control app on setup, but I just always check it as such on my own.

I noticed that when I press and hold on the music control widget in order to change the music control app, Smart Audiobook Player doesn't come up as a choice (it remains checked in the settings).

On a side note, when I tried to uncheck the automatically chosen music apps, after closing and opening the settings they were ticked back again on their own.

Any ideas?