Network Not Available
I have a ZTE Zmax 2 from AT&A. It is unlocked and with Android 5.1. After joinging FreedomPop several weeks ago, I haven't been able to make call or get online unless I turn on Wifi. If Wifi is off, I always gets "Network Not Available". Meanwhile, I live in Cincinnati area which should have very good FreedomPop signal. Lastly, the phone shows full strength 4G signal on the top bar. Can someone help me out? Thanks!