Nvidia: 8k breaking after update from 545 to 550


The Manjaro live image 23.1 includes the prop. nvidia driver 545.
Booting with this, 8k/60Hz works immediately (nvidia 3050, 8K Samsung TV).
After installation it still works.

However, when i do a system upgrade which includes nvidia-550, 8k is no longer working.
The resolution is still offered, but after some flickering it just returns to 4k.
(xrandr also still shows 8k/60Hz as available)

Updating the kernel from 6.6 to 6.7 (and rebooting of course) does not change the situation.

How should i continue?

Should i use nvidia’s installer and try this nvidia-bugreport thing?

Thank you!

Following, live CD runs 4k@120 for me no problem, fresh install fails and only supports 4k@60 stable.