So this bug is still happening. Crossed the server border and was going 56km/h. We tried having everybody disembark or having the commander embark as passenger and various combinations of players as passengers but none of that worked. What fixed it was the commander disembarking, logging off and leaving world. Logged back in and I was going normal speed. I have no idea what caused it but I suspect something caused me to become haunted on the transfer between servers.