The name attribute of a user is quite restricted based on security so this is probably your issue, you can quickly test it by getting your own user account as an owner of the object and then view the data again. You will probably only be able to view your own user name. You can solve this by using the Account specialization instead of the user entity itself.
Do update to the latest version of module Data Widgets. See if it helps.
If not, see if Hunter's solution helps.
If not, create a new app showing similar bug and create a ticket at support@mendix.com