I played the game for hours earlier this morning without any problems at all, but when I started a new game 20 minutes ago it started to happen. I have made no changes to any of the settings. V-Synch is off. Frame Rate Unlimited. I use a RTX 2060 that has given me zero issues at all. I uninstalled all Mods to try and see was it related to those, but it happens in the vanilla game too.
The screen will turn off, and 5 seconds later turn back on again as the game continues to play. It will keep doing this until I exit the main menu where it stops.
No new patches have been downloaded between early this morning and later in the morning when I went back to the game and started a new game, level Hard, France v Abbasid Dynasty.
Edit: Purchased through XBox store, play on PC.