A unique ID needs to be deliberately set by a unique ID special value. It’s an auto generated value, but needs to be set by the special value column. It’s not automatic in the way that Row ID automatically fills in whenever a new row is generated. Is there any reason why you are not using the Row ID in place of the Unique ID? Are rows automatically added by the User Profiles process when a user signs in? Is your Complete Profile screen just a details screen? If it’s a details screen, I don’t think you will have access to the Unique ID special value to set the Unique ID column, like you do when you are on an Add/Edit/Form screen, or the AddRow/SetColumns actions.
Basically, you need to set the value. It won’t automatically appear. Only Row ID does that.