Hey Guys I found the issue, just incase someone else has this problem in the future I’ll post it here. It wasn’t an Unreal Engine specific problem.
When I clicked to focus on Unreal Engine, my GPU usage dropped to 10%, when I clicked off, it would rise to about 40-50%.
FOR ME it was my graphics driver, so I installed DDU (driver uninstaller), uninstalled the nvidia graphics driver, then reinstalled it, and now everything works fine.
BUT do not assume it will be you graphics driver, because the only reason I found out this solution is because someone had a similar problem in a video game they were playing and FOR THEM, it wasn’t the graphics driver the game was waiting on, it was the keyboard and mouse drivers, when they focused the game it would lag, when they unfocused the game it woudn’t lag, same scenario. So they just used a ps4 controller instead of using their keyboard and mouse and boom, max fps, no lag.
fortunately for me, unfortunate for you reading this, I got lucky that it was just a graphics driver, apparently it can be like any driver at all, and I have no idea how to check which driver its waiting on, I just took a guess, so good luck future people.