Moving medical records between devolved nations never used to be a problem in the days before everything was digitised... when I moved to Scotland, my GP in England simply sent over my notes and that was that. Simple. Now, neither system (or it seems devolved NHS organisation) speaks to the other in a timely fashion, and it seems they are equally annoying in this regard.
The strange plus of apparently landing from outer space, is that I was able to book my Covid booster, which I received yesterday, and have been offered breast screening (15 months after the last time) and bowel screening (3 months after the last time) so I am happy to accept each of those. I am assuming that my new GP has taken some notice of things I stated on my registration form... such as left arm only for vaccines (the vaccinator knew this yesterday) and that I don't need cerivcal screening as I no longer have the necessary anatomy! My flu vaccination is booked for a couple of weeks time.
I've been very well served over the years by NHS Scotland, and have to say in all honesty, it's very much so far, so good with NHS England.