Rhinoceros 8 + Apple M3 Max MBP : Awful results, issues, impossible to use..

Hi,
Just wondering if this happened to other people than me..

Recently, I had changed my beloved Intel MBP 2017 running Rhinoceros 7, for a brand new 4000Euros MBP with Apple M3 Max with tons of expensive RAM, running Rhino 8.
First results was that with the option on rhino " OpenGL available", I could not even use the software with lack of lines, I had to decrease to Open GL 3.3
I recently saw that this thing could be solved with a little prompt line that I added, but results are even worse with extremely low software.
Result is an extreme lag, so extreme that even classic options while using the mouse ( like Control holded) takes so much time that the button is not even considered.. If I hold a tool box to make happend the sub, it can take up to 3 seconds to do it.. nightmare.

I just don't get, I should have done something wrong.. but really, results are awful and I am worried. I wish I could use the mac version of Rhino, but I am a real fan of the Windows version, for a sentimental reasons, and also more direct display, productivity.

By what should I start to debug this?
many thanks for your help.

 

Nobody ?