I had it on multiplayer , my bike moved once but my friends moved just a little every time he got off , we ended up re starting thinking it was a bugged map or something but have seen that its happening to a few others , I don't have mods on my game yet , trying it without first. in the end I was picking my mates bike up to give to him to replace and held it a bay for a little while but I know at some point it did it again so I just picked it up n dropped it for him . So far its the only problem I've had .