I updated my iPhone and iPad and both asked for a code, but wouldn’t send it to either device because neither one had been authenticated. Apple ID Verification code not received so i call to apple support phone number, they took two hour long to sort this out. Seems that the system had sort of half authenticated both. Part of the system thought they were good but other parts wouldn’t trust them. All is well now but there’s an important lessen here. When iOS updates come out don’t do all of your devices simultaneously. Finish one and get it authenticated before doing the next.