I'm on another PC now. It's much better. 6 per row, Win-10 64 bit, 27", Firefox 136. (and a lot of plugins).
I'm not near the other machine now, but i'm pretty sure that the version of Firefox is older on that (not a single plugin in that browser), so it's must be something with that. I did checked the possibility with zoom.
But it worked fine before the update, and i used the other machine to visit the site many time without that error.
PS: I'ts fine by me. This is my gaming machine and the one i up/download mods on.