Panicking slightly about what this is all about - is it that the university and UCAS aren't in sync or do I need to contact UCAS/Birmingham?
Any advice would be appreciated
You'll also not be eligible for adjustment or clearing.
It is VERY early in the cycle to be choosing a firm choice officially. There is still 7 months before the deadline.
Anyone who is reading this and thinking about choosing their firm/insurance on track PLEASE don't commit this early on. Every year TSR has dozens of threads from people who pick their firm/insurance early and then change their mind and their options are extremely limited.