zavenous: Here are a few ideas:
Did you reboot after unplugging the monitor - does it still do it if you switch to windowed mode?
+ Are you using MODs - which version of Windows are you using.
+ Did you update drivers recently (try to get newer drivers or rollback or the previous version).
+ What change could have you done on the PC since it started happening.
+ Did you try disabling your antivirus or security solution to see if it was changing anything?
+ Misc. last one I could think of - what is hte refresh rate of your monitor set to?
Hope this helps!
P.S. There is a new update coming tomorrow so make sure to try in a day as well to see if anything changed.
Also try to reinstall the game / check the files if it still fails!
Also - check if you have Discord or something similar running I heard that using Discord can result in weird behaviors!
It was a problem with playing on fullscreen. I used to play the game when it came out and never had these problems . but i randomly made it work with tweaking some stuff and I think borderless fixed it. Thanks for the reply