The game won't 'full screen'

Not sure if this is a known bug or not, but I'd appreciate some help.

I loaded up the game yesterday to tweak the settings before the early access began. 

When the game loads it only takes up half of the screen, as if it's displaying in portrait mode instead of landscape (pic 1).

I've checked my display settings on my monitor (pic 3), all good. The in game settings are normal as well(pic 2), except for the refresh rate being locked to 0.03hz for some reason. 

I don't know why it's doing it, and I can't seem to change it. The only work around I've found is to set the game to windowed, but then I still have the tool bar and border at the top showing, not very immersive...

And for some reason, clicking on the desktop actually makes the game full screen, but then clicking anything else takes it back to the half screen. Video attached.

I don't know if you need this, but: recently upgraded to win11, 3080ti, Ryzen 9 5900x, 32gb ddr4 ram, Asus strix b550-f mobo, plenty of power and plenty of storage.