JabRef version 5.0 / 5.1--2020-08-19--9adfd5b on Ubuntu 20.04

Linux 5.4.0-42-generic amd64
Java 14.0.2

• Mandatory: I have tested the latest development version from http://builds.jabref.org/master/ and the problem persists

Preferences that I make in the Options -> Preferences are not stored at all. Namely, I want to change the default Key pattern to [auth:lower][year][veryshorttitle:lower]. When I click save and open the Preferences again immediately, I see the default key pattern again.

I installed both the stable release as well as the development version using dpkg -i. Might this have to do with the way I installed it and hence messed up permissions on any config files? I also don't get an event log.

Steps to reproduce the behavior:

1. Open Options, Preferences
2. Go to Citation Key Generator
3. Double click the Default pattern "Key Pattern"
4. Enter desired pattern
5. Click Save
6. Open Options, Preferences
7. Check Key Pattern -> it has not been saved.