Metadata not synchronized

[Charon1212]

I run the MinimServer Starter license on my QNAP TS-128A, and the installation process and setup was quick and easy.
After the initial scan of my audio library, I tweaked some metadata, as well as deleted some audio files.
Although I did several rescans of the MinimServer, all the old entries still show up in my WiiM App.
Any idea how to solve that? Is this problem related to the WiiM App, or the MinimServer?

Thanks for comments.