We chat about videogames and videogame accessories.

Okay, my amateur advice as someone who had different problems relating to running games in fullscreen and who glanced at Google for a few seconds:
-Right-click on the icon for one of the affected games.
-Click on Properties.
-Go to the Compatibility tab.
-Try checking and unchecking different boxes there. My particular issue was solved by checking "Disable display scaling on high DPI settings", which basically fixes the size of the play area and makes the rest of the screen a black border. (Sometimes said play area is really tiny, but it's an improvement over what the game was doing before.)
-If that fixes the problem, do that for your other games, you're pretty much going to have to do this one game at a time.

I don't know if that will help, but it's the best starting point I can offer. Hope you figure out what to do.