Low Fps even at medium settings

[ItalienSturm]

I went on a nostalgia trip an decided to play all the Settlers game, but I found a problem that stops me to enjoy it.

There isn't much to say: after fixing the resolution to a 1920x1080, during game my framerate was around 15-20 fps, blurry or overly-sharp. I tried various settings but with no avail and I'm stuck with the lowest graphic.
Perhaps my PC is too new? I have Win11, i7-12700K and a RTX 3060.

Yet, I can perfectly run The Settlers: New Allies and the previous one, Settlers Rise of an Empire, look way better.

The web doesn't give much infos, Ubi is useful as always, and so, who can help me?