I would retrieve the account object over association in a dataview, there you can use the reference selector.
The reason this doesn't work is that the association that you are using is part of the user entity, and you are trying to access it directly from the person entity.
You might want to let Person inherit from Account, then it’ll work.
Thank you. We are now using a nested Data View where the Data Source is a microflow that returns a retrieved Account, if found or else a new Account object.
And in case someone needs this, this is the SavePerson workflow we use in Person_NewEdit: