VALORANT FPS drops down permanently after alt tabbing

Heya, whenever I alt tab out of Valorant my FPS permanently drops down from 400 (where it's capped at) to 120 and stays that way until I restart the game. My specs should be more than capable of handling the game FPS wise to keep it around 300-400 but alt tabbing permanently reduces that number to 120 for some reason. I have the game running at 4k with an RTX 4070ti, Ryzen 9 5900X and 16gb of DDR4 RAM. As for solutions, I've tried disabling full screen optimisations for the game, and tried some settings in my nvidia control panel which did nothing to fix the issue. GPU drivers are at their latest as of today since a new driver released (vers 531.41). I'm using Windows 10 as my OS. Any ideas?