Hi,
i have the same Problem with my Webpresenters HD (not with the 4k and 720).
When i use Microsoft Teams the complete Video from Webpresenter disappears and Audio only is working.
On the Webpresenter Preview Screen connected via HDMI i dont see any issue.
The Problem comes from the Slides you present. When you switch to an other Slide or Video the problem is gone.
I was in contact with Blackmagic Support (September 22) and send them my Test slides so they can check it on their systems.
They told me they have the Same Issue and will send it to the Software Developers to fix it.
Last Answer from Blackmagic:
Our developers are still investigating this behaviour. If an update does come it will be available on our support page linked below.
I can not comment on time scales of any possible resolution.