I have a Surface Book 2 connected to an ASUS XG35VQ via a UD-ULTC4K. All is behaving fine (charging, USB, monitor) over both DisplayPort and HDMI except for when playing video.
Youtube videos for example (both in Chrome and Edge) freeze after 2 seconds and then play one frame about every 7 seconds.
Most crucially Microsoft Teams calls suffer immensely, with incoming video freezing alongside audio for about 5 seconds at a time. Connecting my USB devices and monitor directly to the Surface Book works fine.
I have attempted to force the browsers/Teams to run on the Nvidia GPU as apposed to the Intel; one, and disabled the Nvidia GPU altogether, with no joy. This also happens with or without the DisplayLink software installed. Any ideas?