Mouse sensitivity inconsistency while playing

What i expected to happen

That the mouse sensitivity is the same while playing

What happened

When i looked around sometimes it would move the camera around smoothly at the speed i would expect but other times it would move so slow, it moves so slow that it would probably take over a minute to turn around.

What i think is the cause

I believe the cause of this is lag as if i stay in one place it happens less than if i load chunks by flying fast