Screen freezes when sharing it via MS TEAMS or doing YouTube Live

I've got a MacBook Pro 15" that I just updated to Big Sur, but this issue happened under Mojave too.

3.2 Ghz 8 Core i9 with 32GB RAM and Radeon Pro Vega 20 4GB video.

When I do a screen share in MS TEAMS I can share the screen successfully for 20-40 minutes, not really a set time, then it'll just crash my screens. The screen will freeze but I can still talk to the students (I'm a university professor). After about 30–60 seconds they'll no longer be able to hear me (nor I them) and I have to do a complete hard reset.

The same thing happens when streaming Live to YouTube or Facebook Live via eCAMM Live software (or direct using their solutions but sharing a screen is nowhere near as slick).

Fans don't go haywire (suggesting it's not overheating)

I'm running two Dell screens at 1920x1080 resolution. One is powered directly from the computer via Thunderbolt 3 to HDMI cable and the other is going through a CalDigit hub. Multiple hard drives are usually attached as well via the hub, but today only one HD was attached.

I also run a webcam (Sony a6400) via Magewell HDMI to USB 3 converter, plugged directly into the computer, not the CalDigit hub.

Crashes still happen in TEAMS even when I disable the webcam by turning it off in TEAMS (hardware would still be plugged in).

Many Thanks in advance for any pointers/assistance you can provide!