@romrom77 said in Weird artefacts then freeze:

I finally tried the raspi os and image is normal, except some buttons ("OK" "CANCEL"...) that don't appear, and some small graphic bugs...

If even on the Raspberry Pi OS you had graphic bugs, and, after all the tests that you did, knowing that with another RPi it worked ... I can only imagine that the problem is Hardware, unfortunately I can't suggest any more.