Assassin's creed mirage fps drops

So I won't be dropping below 60fps and it's not constant.

So when these little fps hitches happen you can tell its happened even though its just a drop of like 4 or 5 frames without even looking at the fps counter you can see the drop happen in real time.

So when them hitches happen if your looking at your gpu usage it will very quickly and I mean very quickly drop to 5% then back up to 88% or 90%.

I have no idea why it's doing this as its barely using any vram or memory and tbh it could use more cpu cores if it wishes but it's fine apparently

Update: just was using msi after burner and I can see in some situations that it will just use a single cpu core at like 83%

Update 2: they added denuvo in a day one patch even when reviewers reported stuttering before the game released, so the single core performance will be even worse with that in the background running constantly