The 11.4 repo is not to be used on 12.1 The versions have different kernels, so that won’t work.
Using startx as a user won’t work, do not try it as root for other reasons. How did you install the driver? Did you follow all the steps from the instructions used?
I found it in YAST. Yes, I’ve added some third party repos Packman as so. I had to reinstall the system, I would like to make it work on this attempt because I don’t think so that I am capable to fix it in the shell. So should I wait for 12.1 repo or try a luck with proprietary ?