Hey guys! Have the same issue where my external monitor glitched out or some crazy stuff has happened with it after Monterey was installed on my MacBook Pro 16 (2019). First annoying thing was that I couldn't log in to the laptop when an external display is connected - after type in the password, it's jumped into crazy colors and offered to type in the password again and again and again. The second annoying thing is that Davinci Resolve crashed every time I opened it on an external display or used display as a video clean feed. Mental. The solution that worked for me was changing the color profile of the external display. I changed it to TV Monitor because my laptop works just fine with my TV. This pushed me to the thought that it's a weird situation going on and I tried a different color profile. Hope it can be helpful somehow.