Preferences / Settings only being saved and loaded if MuseScore is run with "sudo", after updating

OS.: Ubuntu 18.04.
I used MuseScore 2.1 as AppImage 64 bit for a while and all preferences and settings were being saved and loaded normally. After downloading versions 2.2, 2.3.1 and 2.3.2 as AppImages, they stopped being saved and loaded if I don't run it using "sudo". Now, they are also not saved nor loaded if I open MuseScore 2.1. But running it as root, PulseAudio cannot be loaded and there is therefore no audio output.

What I tried so far:
Renamed the folder "MuseScore2" in my /home/name/Documents directory. When I opened MuseScore 2.3.2 again (normally, without using sudo), it created a new MuseScore2 folder there. That means it probably saves the preferences somewhere else, but there is no clue on where it does and the documentation does not say anything about it: https://musescore.org/en/handbook/preferences

Tried to install musescore from the Ubuntu PPA instead of using the AppImage. Nothing changed, still the same behaviour, only loading preferences if I run it using sudo.