The answer
The customer account, billing details and registered domain holder have different roles. Editing a profile does not transfer an existing domain or automatically update its holder details.
Contact us with the domain name and describe the requested change. We will clarify the necessary information and confirmations with you. Only provide identity documents if specifically requested through an agreed secure method.
What to do
Note the current domain name and requested change.
Contact support from your account email address.
Wait for the required confirmations before assuming a holder change is complete.