KORE plays wrong song

KORE 3.1.0 on Android 10 (Sony XPERIA XZ2 compact),
OSMC/KODI Build 20.3 (20.3.0), GIT 20240128-osmc (Raspberry 4), no updates (updates gradually made a previous installation unuasable)
KORE remote page -> hamburger -> music -> Albums (or genres,…) -> (select whatever I want) -> something entirely different plays
The same happens with hamburger->Movies or TV shows- I never get what I select
The catalog is newly built, tagging and file names should be ok
There is no problem selecting anything via hamburger -> Kodi files (which could remember the previous directory for Video/Music/Pictures, but I digress)
What might be wrong?