The other day my dealer had to stop my application. A message came up saying it couldn’t go any further until I contacted motability directly.
After a bit of a wait on the phone it was all sorted.
It turned out when I handed my X1 back during the transition from DLA to PIP Motability put an automated hold on my account. It was done with everyone at the time because some people held onto their cars while no payment was coming from the DWP so they actually owed Motability money. I assume some people tried it on a bit so this is their way of getting that money back.