Sadly, I just replaced my Surface Pro 4 (bulging battery and only a 90 day warranty with that unless you get a new one) and was seeing the exact same issue with one of two screens dropping out and coming back. I'm running dual 3440x1440 ultrawide LGs on
a Surface Dock. What seems to have worked for me is this.
- Reset the Surface Dock, which is something I usually try first anyway. (still did it)
- Flushed the display with the registry file on this thread. (still did it)
- Validated that the Surface Dock was up to date (still did it)
- Manually updated to the latest driver (still did it)
- Finally, looked at all the modes and changed to one with a slightly lower frequency THIS!! (seems to work so far)
Check all your modes. Mine supports 3440x1440 @ 60Hz and that is the recommended mode, but it was dropping and coming back.
Once I changed it to another mode that was supported, in this case 3440x1440 @50Hz, I have not seen the flicker. It has only been a couple of hours, but it seems to be working.
I think this is only a workaround as it should be stable at the 60Hz as my SP4 was.
You can get to this via the Advanced Properties.
