Apple Music not playing some songs

I'm using Apple Music since when it was introduced as "iTunes" on Macs. My library has some thousand titles and when Apple started iCloud synchronisation I opted in and uploaded it.

Recently I found though that some titles are no longer able to be played. They are listed normally in the Library and I can even download them and play them with third party software (VLC). Neither Apple Music nor Finder preview plays the title though. Other titles from the same album are played.

I already tried to turn off Synchronisation, restarted the Mac and turned it back on (had to reboot a second time after that to get the sync started). The issue is the same on my other devices (checked on second Mac and iPhone), too.

Any ideas what this might be and how to solve it?