Hello,I have a CHSTEK HU CPU UIS7862(S) 8G/128G and I am having issue with using 4G. I have a Tracfone sim and have checked T-Mobiles site and they list the SIM as compatible.It will work on and off and the indicator bounces from 4G to E, when it show connected to 4G it works fine until it displays the E next to indicator bars. The cycling is continuous every 5 or 10 minutes. I have tried several different APN setting including ones for Tracfone and TMO and the results are the same...Read more