Question Massive Fps Drop

[MatrixHacker]

[Specs]
CPU-i7-8700K
GPU-GeForce GTX 1080 Ti Fe
RAM-Corsair Vengeance rgb pro 32GB
MOB-Z390 AORUS PRO WIFI
PSU-850+ Gold Evga

Here's a clip I got of it doing it and it does it even when im in my inventory just sitting there, yea it does it in other games so im not sure what to do I run them in 1440p at high and sometimes highest, usually I play most of my games in borderless fullscreen but I put it in fullscreen because it seemed to help a little.
And btw its not a laggy video thats just what it looks like in game when it does that.

https://imgur.com/a/uA6EDBq

 

[rgd1101]

cpu/gpu temp and usage during the game?
ram/ssd usage?

 

[MatrixHacker]

even when i turn off my pc all night and start the game in the morning it still does it, the temps are around 44/65c when i first load up the game, playing for about 6 mins the temps are 54/85c usages are at cpu-minimum 68-96 gpu stays around 96-100 ram stays around- 39 and ssd-it says 0% and its a intel 660p