After engaging some enemies (after a combination of aiming and firing whilst prone and standing, switching interchangeably between the two etc) my character is unable to move forward or sprint/run forward. Any other movement that is allowed is very slow. This is only experienced when using the xbox controller with default settings and DOES NOT occur during multi-player, only campaign etc. When this happens, it is still possible to move forward using the "W" key however is very slow as you cannot run. This happens during play-through every time without fail and is becoming frustrating as I would either have to load a save or restart mission.