@dirtychinchilla surprised you've only contacted your GP now as you should have been either group 4 or 6 at the very least before now.
My colleague was diagnosed a few years ago, and compared to myself (18+ years now), is in a worse position with his condition and was taken out of being in group 4 some point last year with no reason. He continued on biological treatments and it wasn't until a call to the gastroenterology nurse (who in turn chased the GP) that got him back into the right group. I share the same gastroenterology nurse (and I guess team as same Hospital trust) and have been on the group 4 list since the start. My GP has been great and I believe that made the difference between myself and my colleague.
I'll find out how things are soon as I've moved house and now recently registered with a new GP. I've had my first Covid jab back at the beginning of February so will be due at the end of April/May for the second if they are still sticking with 12 weeks apart.