App Store invalid email issue despite Apple ID validation

I have set up an Apple ID using an email address an password, Apple ID has validated the email address with sending a code to the email address which I have then put into the phone and this has been accepted. I have then gone to the App Store to download authenticator apps in which it’s asked to review the Apple ID info (inputting a billing address and credit card) after inputting this it keeps advising the the email address is invalid even though it’s already been validated- I set up our company phones all the time and have never faced this issue before, how do I resolve this? (I have downloaded any updates on phone, sign out of Apple ID and back in, changed password, reset the phone and set up again, turned off and back on

[Edited by Moderator]