Here is what has been found with my lg g4, I apologize for the fact that I am not tech savvy at all , but will offer this. I signed up for verizon edge on June 17 with the purchase of lg g4. right out of the box the phone would drop calls, and have terrible signal issues, my brothers phone would read 2 bars of 4g lte and i would only have 1 bar of 3g. and these phone were sitting side by side. Long story short, sent phone not LG, and they found that the "mother board" had a crack in it. Obviously a manufacturing problem, but they wont admit it. They "LG" would not warranty the fix and did not repair. So called verizon and they are sending a refurbished phone. Not Happy. I don't know how to attach the picture they sent me or else i would. I don't know if this is the culprit for all of us, but you may want to check....