I have a couple of more suggestions for investigation:
- When you uninstall an app via “Software” by clicking on the trashcan, you are prompted whether to keep or delete app settings and data. Does this make a difference? If you keep them, then reinstall, does it start once or not at all? It could be that something in the settings written after the first run, messes it up? In that case deleting data from
.configand.localwithout reinstalling would allow you to start it up once more? - Can you try entering the flatpak with the command below and see if you get any more messages? (I used this in this discussion for a similar issue).
Command would be something like:
user@host ~> flatpak run --command=sh --devel --filesystem=$(pwd) net.xm1math.Texmaker
[📦 net.xm1math.Texmaker ~]$ /app/bin/texmaker
...