Still having similar problems, now reconciled to it being a high spec expensive piece of kit that just doesn't work very well. Stopped the Sophos VPN as advised that could be the source of the problem - removed completely - little (no) difference or improvement.
It's slow. Takes some while for apps to open. Can just stop mid-process, only way then is to either kill that app and relaunch (works sometimes) or do a reboot (if killing the app doesn't work). No pattern re. apps, can be any, at any time, and not when under any real task.
Compared to the Intel Mac Pro it's third rate, although that machine, after nine years wasn't able to run the latest updates of OS. Ironically if running the OS of eighteen months ago, it would probably still be excellent as the 'crashing' started shortly after on (interim - mot major) update.
Doesn't like Bluetooth, takes ages to connect to either mouse or keyboard (latest model) so I now use the keyboard wired. Quicker and more reliable (i.e. it responds). Even connectivity with drives - via USB very slow - compared to the old Thunderbolt.
Had to spend on new M chip apps, didn't see that cost coming.
Overall - definitely would not recommend........
Studio Mac - a very poor product, big step backwards. Nothing that is even a patch on the former MacPro cylinder.