Kore uses special characters while downloading tracks

Hi!

I’m using kore 2.2.0 (from f-droid) with Lineage OS 14.1 (Android 7.1.1). For downloading tracks kore uses the title of the track as the file name. This fails if there are special characters in the title like “?”. For example kore tries to safe the track “Foo Bar?” to the file “Foo Bar?.ogg”. This fails and results in a file called “Foo Bar”. This file can’t be played by the music-player. Renaming it with the filemanager to “Foo Bar?.ogg” (yes, with the special character) makes the file playable by the music-player. Is it a charset problem? Or any other hints?

Thanks a lot!