Re: I feel left out
>Apparently I can't update it either as my domains are held by 123-reg and it is up to them to update Nominet - a process that apparently is supposed to be automatic.
No, the process isn't totally automatic, 123-reg as a result of GDPR don't automatically pass what could be PII data to Nominet. You need to call 123-Reg and ask them explicitly to remove the privacy flag from your 123-reg registration records to enable the automatic data exchange with Nominet, then wait a few hours.
Don't remember seeing it documented on 123-Reg website, but Nominet UK support told me what the problem was when I encountered it last year.