Thanks for your help, Sven! Video goes black on webcam output and multiview. I’m also feeding audio via mic #1 and it continues to work while hdmi #1 goes blank. I’ll do a load graphics test tonight (the ATEM is acting as a audio source during the day along with a backup webcam). I also ordered a Cam Link 4K to test the X-T4 and also planning on testing hdmi #1 and #2 with a the newly updated Filmic Pro and my iPhone just to get more data points.
On the randomness, the daily startup routine is to power up ATEM + lighting + MixPre/mic, then turn on X-T4. Once all is powered, a quick check with MS Teams to ensure A/V is working as expected. This workflow has always resulted in successful test results. Throughout the day a zillion MS Teams calls happen of varying lengths. For two weeks there were no failures. Starting this week, HDMI #1 video for the X-T4 would go blank after an hour or two. This streaming rig is permanent, so I can follow whatever configuration/power up/down protocol that works reliably (e.g. can leave everything running since all the connected devices are relatively low power draw, and the lighting is standalone).
Root cause analysis is not going well given prior successes, no Win10 updates/device configuration changes, etc… My short term plan is to swap the ATEM for the Cam Link so I can do more thorough testing and hopefully find a pattern or two.
One last factor is that the target laptop is a “corporate” laptop and totally locked down – that motivated my using the ATEM instead of OBS/et’al.