I'm surprised and annoyed with the lack of support on this issue. I have now found the solution using trial and error working through the issue on my own during the past few weeks. Not what I expect to do.
I upgraded my iPhone to an iPhone 12 mini a few months ago and utilised the automated data and profile transfer process. All seemed OK and, whilst suspect, my region settings were correct for the UK.
When accessing the App Store, its not clear which App Store it is. Which region? My iPhone was setup correctly for the UK, but it became apparent after trying to update, or access a number of UK/European Apps that the App Store I was looking at was perhaps not for the UK despite my region settings. I assumed it was now registered with the USA App Store as a default.
I changed my iPhone's region to the USA and logged into the App store. I then changed my iPhone region back to the UK and re-entered the App Store. This time, it asked me for a Payment Method. I don't normally do this for security concerns, but in this instance, I entered a payment method. Voila. It now works correctly and I can now access Apps I couldn't do before.
It is apparent that despite my region settings, the transfer process to the new iPhone does not complete the profile transfer correctly and does not register you correctly with the appropriate App Store for your region. Moreover, it does not inform you that it hasn't registered you correctly.
I have since modified my profile to remove the payment method and my access remains with the UK App Store, so I'm back to where I was with my old iPhone. Thanks for lack of assistance Apple.
