Under 16s account ERROR - Something's gone wrong, please try again in a few minutes

Hi all. I’ve finally got the email through to activate an under 16s account (took roughly 2 weeks after joining the waitlist) but once I put in my child’s details and go to confirm it is me with my pin, I’ve always been met with the same error:

“Something’s gone wrong, please try again in a few minutes”

I’ve restarted my samsung S23 Ultra phone, cleared cache app data and normal storage data, updated the app, changed WiFi, tried Cellur, uninstalled and reinstalled the app, but always getting the same error. Have even tried now signing in on my iPad, but get the same error again at the same stage. Anyone else having this issue or know how to fix this please??