Mac Pro 6,1 on Sonoma and Studio Display - Camera not working?

Hi everyone,

I just picked up a Studio Display. So far I love it, except I'm having difficulty with the camera. On FaceTime, it's just black and says "No Video. FaceTime has not received any video from the connected camera. Restarting your computer may fix this issue". Restarting, switching TB ports, toggling CenterStage makes no difference. I have a mid-2015 MBP on Monterey and the camera works right away, CenterStage works too. So that's why I'm wondering if it's something with OCLP.

Here's some more info on the hardware:

-Mac Pro 6,1 8-core, D500s on Sonoma 14.4.1
-MBP mid-2015 on Monterey 12.7.4 (non OCLP)
-Apple Studio Display, firmware ver. 17.0 (Build 21A329)
-using OWC TB2 cable with Apple TB2 -> TB3 adapter

Any ideas or similar experiences? Any input appreciated. Thanks!