Yes, there was a fix.
I messaged the OP of this thread as he had the same issue as me:
https://www.e90post.com/forums/showthread.php?t=1587346
He very graciously assisted me - it appears in my case it was some kind of "coding" issue and not a fault with any sensors/modules.
As for how he actually fixed it I have no idea, but it involved a BMW specific OBD cable plugged into my laptop and some settings entered into either ISTA-D or NCS Expert, I don't exactly remember what.
Good luck!!