Raymond. This trips lots of people up.
You are creating new records and want to prepopulate a reference field. You pass the ID in, either as a condition or as a prepopulation (in the create new row action) or as a subsequent field update action. What do you find: Just the ID… Boo… We all want the name!
The problem here is that we don’t have a real salesforce record yet, we don’t automatically run a queries on the user object to retrieve the name that matches that ID. Without the data in the model, all we’ve got is the name!
The solution here is add a second line to your pre-population where you force the name into the parent object. See below how I’ve done it for tasks. 
Then the name value is in the model and can be displayed.
Can’t show what you don’t have…
