Removing one song from a playlist doesn't avoid the song to be played while playing the playlist...
Imagine we have a playlist with 3 songs:
A
B
C
And we remove the B song from the playlist.
Once the A song will end, the B song will start playing.
This is solved by restarting MusicBee.
Windows 10, version : 3.2.6902
Thank you for the job done in this program!