Full screen problem (Fallout 4)

When you switch from windowed mode to full-screen mode in the launcher, it starts flickering like an epileptic's bad dream and flickers for about 30 seconds even after the process is interrupted through the dispatcher (and going to the dispatcher is also a problem). What could be the matter here?

Ps I have a litsuha, unlocked via vpn. in the window all the rules work, in the full screen they * i. Alt + enter do not work. i7, 12 GB of opera, GTX 870, I have a discrete, tried to change the settings, firewood, to no avail. and such a problem as I looked not only at me.