Lars-Eric, did you ever find a solution to this issue as I have started experiencing exactly the same issue.
I noticed a digital tear (glitch) on a static image when streaming via the Web Presenter HD.
- mpv-shot0002.jpg (532.08 KiB) Viewed 4010 times
A 3rd the way down the image you will notice a blurry region running the width of the image. This blurry region pulses every 2 seconds and is not noticeable on moving images.
The cadence of these pulses is in direct correlation to the GOP size. In this case I was using the factory setting -
YouTube - Streaming High which, as far as I know (and as YouTube requires) the GOP size is 2 seconds. If I match the Streaming High settings and change the GOP size to 5 seconds and upload my user-modified XML** to the Web Presenter HD the pulses occur ever 5 seconds. This glitch is not noticeable on the Web Presenter HD's monitor output.
**Just a reminder that Blackmagic's Support department does not / will not support your Web Presenter HD issue if you are using a user-modified XML file.
Using the factory setting
YouTube - Streaming High setting I played a test video from Blackmagic Media Express through a Decklink Mini Monitor 4k and into the Web Presenter HD and got it to stream to YouTube. Once the file had finished playing back I stopped the Web Presenter HD from streaming and immediately started playback of the same file from within OBS and got it to stream to the same YouTube livestream.
From 0m00s to 01m35s is the Web Presenter HD and from 01m36 to 2m50 is OBS.
Has anyone else experienced this type of tear/glitch and know what the solution might be?