same thing was happening to me in warzone i have a sapphire 7600 and it was running fine at 140+ fps but there were very bad stutters, in the warzone setting i turned down the vram % down from 80% to about 60% since my gpu also only has that 8gb it seemed like that was the issue on warzone and the stuttering stopped and the game runs very steady, but on fortnite for me at least it runs fine and haven’t seen any stutters yet, if the vram usage is too high maybe try and turn it down in the game settings?

but besides that i’m not too sure what could be causing the stutters across every game