As i mentioned before (earlyer in this topic).
You need to make sure that HDR is supported.
Multiple Monitor setup , Monitor brand / Specs should (if possible) be the same, color depth , same type cable for connection to the gpu.(only HDMI or Only DP ect) ect ect ect
There are a lot of topics at the internet about this issue , some issues are caused by Windows 10 / 11 it self , some related to Display driver !.
Also multiple screen/display setups could cause issues, different refresh rates, different resolutions , diferent color depts , HDR / SDR ect ect ect.
Also meke sure youre monitor is installed in device manager , ya use the correct color profiles ect ect ect.
Monitor settings could also cause some issues , if 1 monitor is in Gaming mode while the other is in Standing mode for example !!!! <<-- Check it
Some software / game need to be HDR enabled in windows first , while other software / games HDR can be enabled in the Game it self !!!
Ya realy need to hunt down Monitor specs / settings ect ect ect
Rollback a drive isnt / cant be done that easy, example -> check nvidia additional information.
For nvidia to rollback a driver version, ya should uninstall Nvidia in windows by using SETTINGS / APPS and delete nvidia driver (make sure ya pre downloaded new driver already).
Hope you guys got the answer / fix , just check internet for it !
Cheers