https://discussions.apple.com/thread/253324255 There is a discussions thread going on discussing this issue. A tentative fix of lowering the Macbook's build in display to 48 or 50Hz while using external monitors is working for some people. I am testing it now myself.

Not an answer, but another person with the freezing problem. Freezing up multiple times a day since the Monterey update. The most common timing is when I'm dragging a window from one monitor to another (dual external monitors connected to my machine), but it can happen at any time. A few times it has happened again immediately shortly after reboot before I even really do anything. Very similar 16" intel i9 MacBook config to user sarguin. Apple - please help. I rely on this to do my job.