Teracube 2e Murena -- AT&T Now Working!

I just got my Teracube 2e Murena and the data plan doesn’t seem to work with AT&T, though I am able to make calls. The apps needing data work over wifi, but not if the wifi is turned off.

Yes, I’ll stop posting on the myteracube.com site and stick to posting here since I bought the phone with Murena.

UPDATE: With a reset to the system settings, the phone now shows LTE on the banner and the data are working! Terrific! Thank you @Sharad for your instructions:
Try a soft network reset. Settings > System > Advanced > Reset options.