Question PC is laggy after boot for couple minutes, then screen flashes black once and its fixed

Qstep

Commendable
Feb 23, 2019
11
0
1,510
Hello, Everytime i start my PC everything is laggy till it fixes itself couple minutes after with screen flashing black once and windows 10 making some beep sound, it seems like its restarting itself.
When i have my other monitor connected aswell which is alot older then the screen resolution will be really small aswell in the acer for couple minutes before it goes back to normal with the same style.
I have all latest drivers.
Monitor Acer xg270hu freesync
GPU GeForce GTX 1080 STRIX, 8GB GDDR5X