So after a Update this bug appeared.
If I try to unplug the second monitor the main one gets active and recognised???
I don’t really know what happened but it were around 1.1GB worth of Updates.
I used the Kernel 5.15.76 (Linux 515) where it did not work.
I tried a newer Kernel 6.0 (Linux 60) and it still had the problem.
Thinking about reinstalling Manjaro but it really is awful reinstalling a OS all the time just because NVidia is a awful company.
youre not the only one with issues on multimonitor setup, what helped others was to rename/delete the
kscreen folder from $HOME/.local/share/kscreen, reboot and test if it helped
Just deactivated the Screen Energy Saving option and it helped. I think the the System did not really tell the Display to turn on again after sleep.
I found fixed,
goto Nvidia setting and select built-in screen select resolution to auto it fixed
This worked for me too. I encountered this issue today when installing Manjaro on a new ASUS laptop.