I don't know how to solve this using system.user.system$owner, but the way I would display the owner / creator of an object is to have a microflow on creation of a Note that retrieves the object that a user is (system.user or a sub-entity thereof) with Xpath [id = $currentUser] and First object only checked, and then write the Name attribute of the retrieved object to, for example, a CreatedBy attribute of the Note entity.