Kernel 6.4.xx updates

I’m running Fedora 38 Kde plasma on an apple iMac 9.1 with nvidia legacy 340.xx drivers (ssd-drive), the highest kernel update that works well with my GUI its kernel 6.4.6, anything higher, I am experiencing an error of being stuck on login loop. I have nouveua blacklisted since with it, I had flickering on my display and some audio issues.

Anyone with the same problem? if yes, any workarounds recommended?

Thank you