UE5 out of memory / lagging

Using UE5 and i have less than 250 brushes / 40 static meshes.

My project has started to get quite laggy when moving around objects, I’ll pick one up and move it then have to wait several seconds for it to appear.
I’ve also experienced my first crash tonight while grey boxing.

Specs:
Rtx3090
128gb ram
Windows 10

Any help would be appreciated, while I know UE5 is in EA, my concern is the memory issue. I can put up with the seconds delay.