I still don’t know what’s causing the crashes, the only thing I can think of is the usual stuff I know you already checked for (Windows Updates, drivers, etc). I doubt it will help, and I’m sure you already tried, but have you tried disabling your anti-virus (or allowing permissions), try running the game as admin, try not using BattlEye (assuming you are), or try as an experiment to see if the Testlive Client also has the same problems? (Testlive can be installed as a separate client via your Steam library).
To be helpful, here is the link to your old post about the issue. Linky here
Another thought, how much RAM are you, the host, using?