Black interference or keying on a lit curtain background

[WillJJones]

Hello Zoom Community, 

I manage a University Television Studio, we use Zoom so remote students may watch and interact with their courses in real time in a distance learning model. Zoom has worked pretty well generally, but for the last while, perhaps since Workplace became the standard, we've had a video issue we can't seem to resolve.

Our Studio space has LED panel lighting on a grid, at the Presenters desk we have a 75" Smart board and behind that a light grey curtain which is lit with an RGB light bar, the colour blue really seems to be an issue with Zoom, as the intensity of the blue light is increased, the video is almost keyed out in the blue areas but black. No other colour the light bar produces has this effect, and using Teams I can't recreate the issue no matter how intense the light is. 

We send Program video to the Zoom Laptop (A Dell) via an Epiphan SDI2USB 3.0 converter. Any ideas on how to resolve this?