I find that I get this issue, with running/crouching/jogging states, etc. can get all being laggy, broken, and be frustrating & not be a good experience at times.

It can be when you're trying to sprint away, you're moving at the pace/speed of a person crawling in prone, or when you're crouch-walking, you can go at the speed at sprinting, etc.

This happens randomly, and can be very frustrating during encounters or running away from danger.

One cause is if infected heavy attack over on top of you, when prone can cause it, but for the most part it's kind of random.