Brits converting previous EU citizenship certificate to new Portuguese residence permit

Hello

So apparently any British national who previously held a EU residence certificate issued in Portugal can now convert it to a different residence permit online. Deadline June 2021. Has anyone tried this?

Details here:
https://brexit.sef.pt/en/

Been trying to register on the SEF website but I keep getting a user registration error. Now is this because I mostly live in the UK? Even though their FAQ does suggest that as previous EU members we were allowed to do this. Have sent SEF an email and tried to call them, no luck.

Anyone experience this or know why there could be an error?

Thanks

A simple solution might be to use a special character in the password selection when registering. It’s not explicitly stated anywhere and the error messages don’t say what the user error is for. However that could sort it.

Our question is a little different. We have a baby due after the June 30th deadline. Although kids can be added to the application currently, what is the process after the deadline?

Thanks