Trouble Connecting on LTE Android phone?

Is anyone having trouble connecting on AT&T LTE network with Android phone. I just changed from an Iphone to a Samsung Note II and I can only connect via Wifi. I contacted AT&T and they had me factory reset my phone and it still will not connect. I tried from an HTC vivid and no connection. Also tried from a Samsung SIII and it did not work. AT&T said they do not see any problem on there end. I requested help from haypi support and they say everything is fine and they can login to both my accounts. I just want to be able to play when I am not where a wifi is available.