Bad performance in Borderless Fullscreen Mode

[Ranebow]

In Full Screen mode my game stutters when I move the camera so I play in Borderless Fullscreen

The problem is that when players appear or I load assets when I advance in any area.. my performance starts to decrease.. and I'm forced to Alt+Tab to fix it

The game has a really smooth camera movement in Borderless Fullscreen but my performance starts to decrease after a few minutes of gameplay.. the thing is that if I Alt+Tab my stutters goes away but after a while this reapeats over and over

Any fix.. workaround?

Thanks in advance

This isn't an answer, however games work best in full screen - this one included. If it's not, that might point to a larger issue > Drivers, Vsync settings, frame buffering, pre rendered frames ahead(this one in particular might alleviate stuttering if raised).
If the game degrades over time - and we can't isolate it as a game only issue - than it's a memory filling issue e.g. GPU running out of memory. That's suspect though, I'd be hard pressed to believe that a single monitor setup at 1080p takes all 2GB.

What are your in-game settings under system configuration and what of your Nvidia control panel settings?