I continue to have this same issue, but it only seems to happen when I share my screen on a Zoom, Google Meet, MS Teams, etc. call. I haven't been able to find any workaround other than disconnecting my external monitors when sharing my screen.
OS: MacOS Monterey Version 12.0.1
MacBook Pro (15-inch, 2018)
Processor: 2.9Ghz 6-Core Intel Core i9
Memory 32GB 2400 MHz DDR4
Graphics Radeon Pro Vega 20 4GB
Anybody heard of any other workarounds or possible fixes being worked on?