This issue has been fixed for me since updating to Monterey / OS 12. 2019 16 inch MBP with a Belkin Thunderbolt 3 Pro Dock, Dell U3818DW monitor, and DisplayPort between the dock and monitor.

Have disconnected and reconnected a few times now with MacOS Big Sur 11.6 and so far so good. I was able to reproduce fairly consistently before. Has anyone else reproduced this issue on 11.6?

Same issue here. Consistent crash when I connect to the dock. MacBook Pro (16-inch, 2019) + Belkin Thunderbolt 3 Pro Dock + Dell U3818DW