Since a few weeks my Unity games are not working anymore on Steam (not flatpak) on Linux Mint.

I have tried Stick It to the Stickman, Olija and Dystopika.
They all behave the same, with the audio starting playing fine, but still on a black screen.
After that, nothing happens and even trying to switch window doesn't work or is extremely slow, requiring a few minutes to have anything happening.

Adding the same games to another launcher (Heroic), makes them work a bit, but eventually they stop at some loading screen and remain there forever.

I am on the latest OS version, I have the latest proprietary drivers from Nvidia, I have tried switching Proton versions and my GOG Unity games all work fine on Heroic.

I don't know if there are any logs I can submit, but I am all ears for any suggestions.

UPDATE: Solved! The problem was with the fractional scaling feature in Cinnamon. Once disabled, everything went back to work perfectly.