OSMC not able to find files on smb share

Hello,

I have a setup of OSMC running on a RPi 3 with a shared database with kodi running on my windows maschine. Both have sources defined for a smb share (running on my TrueNAS if that matters).
I used to have the shares and the mysql server on another windows maschine, but this one is very outdated. On the old setup it worked without problems, but on the new one I can only play videos when on my windows kodi.
I changed the SQL server in advancedsettings.xml and changed the shares in OSMC gui. I can also navigate in the files tab and even start video files there (they play just fine). But in the library mode for movies or tv shows when I want to start it says ‘file not found, delete it from library?’
Is there a known problem like this or has anyone a suggestion how to find the reason for that behaviour?

Thanks in advance,
Anduril