99% sure they said they are working on it but haven't been able to work out what is causing it yet.
Could be wrong but I think that was said.
Its super frustrating when your going for the flag, stuck in slow, no horses nearby and your teams morale is melting away!
Strafing while moving forward gives you a moment of speed for just a second, which could potentially save you from an incoming cav charge if your stuck in this bug