Troubleshooting: "Account Property" field
If you create or update an Account property, the update appears in the Grid for a given List object (opportunity, lead, etc.) only if the object belongs to the same Account that is associated with the Account property. The Account name for the List object and the Account property Account name must match exactly.
Likewise, to copy information from a Grid field into an Account Property field, the List object must belong to the same Account that is associated with the Account property. If the Account property was set up as single select or multi select, make sure that the field heading and the Account property you want use exactly the same terminology.