Mac Studio Ultra won't sleep

I've just received my Mac Studio Ultra and have been setting everything up yesterday and today. The biggest problem I'm having right now is that the Mac frequently doesn't want to go into sleep mode, and when it does, it will wake up a few seconds later and all the open application windows will be bunched up into the bottom left-hand corner of the screen. I'm guessing this might actually have something to do with the screen/s, but I'm not 100% sure.

I have x2 Benq 32 inch PD3220U (4K) Thunderbolt 3 displays connected to the Mac, both scaled to an effective resolution of 3008x1692 pixels. I have tried un-plugging one of the displays, but I still experience the same problem. Previously I had one of these Benq displays connected to my iMac(2020) and I never experienced any issues – so I'm a bit stuck for answers at the moment as to why this would be happening with my brand new, top-spec Mac Studio Ultra – and I'm not too pleased about it either!