Yeah well I don’t use flatpaks that much so I had no clue about it.

I found out the issue was in the launcher I installed. I tried to look at the Game Directory but the launcher wouldn’t open it. I then installed a launcher from another surce, which was the one recommended by the minecraft website (I know I should have used that from the beginning), and the game was correctly installed in the right directory. I was then able to see all my previous worlds correctly. For Arch linux users: the Flatpak version of the launcher didn’t work correctly, at least for me, the AUR package is the correct one.

I could but my home folder is pretty big, launching a search process throughout the home or the whole system would take ages so I would like to avoid it if possible…but I can try if there is no other solution.