I am running Manjaro (Mate) on my laptop with an Nvidia graphic card,
and I cannot get use the full resolution (3440x1440) of my external 34" Dell monitor, it won’t show the desktop correctly. If I set the resolution to 2560x1440 it works fine.
[Uploading: IMG_20201212_153144.jpg…](This is what I get with the max resolution. I had to take a picture because taking a screenshot showed a normal image of the desktop!)
Before switching to Manjaro a couple of months ago, I was a longtime Ubuntu-Mate user and the external monitor setup worked just perfectly well.
Any help appreciated!