Alt-Tab fix

[Stay on target, Porkins!]

So, I recently upgraded my rig, and combined with the latest patch my performance has been boosted massively. I can now play on megalomaniac maps with almost 60 fps in most areas. However I get these bizarre frame-rate drops that can be quickly fixed by alt-tabbing and returning to the game. I saw a youtuber have the same issue with the game and I think this was pre-June patch. Anyone have an idea why this happens and why alt-tab fixes it?

Just to add, I have used the Borderless Window app with the game and other than maybe upping the main frame-rate up by 2 frames or so all round, it hasn't stopped this issue from occurring.

[CunkFeatures]

Maybe Alt-Enter? Then fiddle then Alt-Enter to fullscreen again?