Have you tried clearing the cache of the T-Mobile Tuesday app? What device do you have? I have only ever seen that issue personally in areas where the coverage was really poor, ie rural West Virginia. What is your signal strength like when trying to load the app?
Worst case scenerio, clear the app data, app cache, then uninstall and reinstall the app.
Just coming in to echo what was mentioned above and see if you had a to try any of the suggestions!