Yes, I think the issue gets confused because lots of people get invited by their GP and receive a link to a website for booking which ISNT a the national booking site but their local GP led booking site.
There are 2 different vaccination systems running...,
mass centres a no pharmacies (booked via national booking site...either after receiving a letter or text from the national service, or after looking and seeing you are eligible in front page, or by just trying to see if the system lets you through as eligible....often is letting those a couple of years younger than front page through)
GP led sites...often in community centres etc. People get invited by text usually which gives them a link to a cooking system or sometimes a phone call or occasionally a letter. The booking system is different and just offers GP led local services...often run by the PCN which several local GPs are part of, perhaps the CCG which serves a larger area.
GP led vaccinations are at vastly different places age wise which reflect differing local supply but mostly different age demographics and efficiency. When you hear of healthy 42 year olds getting it, it is in areas where GPs are ahead, unless they are in Group 6 with an unknown medical condition or caring responsibility or job with NHS or social care, or learning difficulty which makes them eligible.
Often people are totally unaware in they booked or were invited by national system or GP led system and if they attended a local GP vaccination centre or one of the mass hubs. It makes it hard for those trying to track it all, to see when they might be next much more tricky.