How to clear library cache of WHA?

[Aquaman]

I‘m running Minim Server onto an Ultra.
Lately I have changed the covers of a few albums, which lie in the album folders as folder.jpg. No embedded covers.
When I browser Minim Server in the WHA it still shows the old covers.
I have run multiple restarts and rescans of Minim. I have even redirected Minim‘s library to another folder, ran a rescan, changed back the libtrary and rescanned again. WHA is still showing the old covers, so it is obviously caching it somewhere. How can I clear this cache?

 

[Aquaman]

Deleting the app and reinstalling it did the trick.