[2021] G-SYNC not working

Slaikkiz said: is the fullscreen just borderless windowed?

That is correct, yes. More modern games are coming out like that, no true fullScreen mode at all.  

Sorry, I thought that question was connected to the G-Sync issue.

I frankly don't know much about G-Sync. Is that something you can ask nVidia about, why a game would or would not be able to use it?  

Good luck with that! I'll be here if we can help any further then.