I am also experiencing similar issues with 3.1. Working with a pretty large scene in Sketchup (100MB) and was trying to use 3.1. I was dealing with constant crashes in Enscape, which then crashes Sketchup. I could barely get out 3-4 renders in a batch and it would freeze/crash.
I also noticed that the rendered versions of the images looked noticeably worse than the live view, to the point where I was using the windows clipping tool to screenshot images from the live view. Other issues were the water motion/wind would never stop moving, even though Restmode is enabled. Also light leak seemed to be much worse.
I am using a Titan RTX card, so VRAM shouldn't be an issue. However, based on the response I received from the Enscape team when I submitted an error report my VRAM is maxing out. I tried a number of things suggested by the team but none of them fixed the problem. I ended up reverting back to 3.0 and everything works fine.
It's very odd because I was just recently using 3.0 on a much larger scene with absolutely no issues. Hoping its just an issue with 3.1 and not indicative of future builds...
UPDATE: I have multiple machines in which I can run Enscape and one of my other machines is a non-RTX card (2 SLI Linked 1070ti). While slower it seems to not have the crashing/memory issue I have with my Titan RTX. The other issues I mentioned are mostly resolved as well. The only issue I am still seeing is the Restmode constantly stopping and refreshing every few seconds.