When using tool_policy as your policy handler, a user must fill out any policy documents before they can enter their account details for email based self registration.

Per the docs https://docs.moodle.org/404/en/Policies#Policies_(tool_policy)_handler

"If Email-based self-registration is enabled on the site, new users will be required to give their consent to all policies before proceeding to the sign-up form. If digital age of consent verification is enabled in 'Privacy settings' in the Site administration, when a new user clicks the 'Create new account' button, they will be prompted to enter their age and country. If the user's age is lower than the age of consent for their country, they will see a message prompting them to ask their parent/guardian to contact the support contact (as specified in 'Support contact' in the Site administration)."

This works well for most cases, however a customer has advised that for user journey reasons it would be useful for this to only appear after account creation is complete - an option to allow the User consent: authenticated users to apply here would be useful