What phone do you have?
Moto G 3rd Gen
What plan are you on?
Does your plan include data, or just talk & text?
Data, talk and text
My phone has recently started changing to GMT time zone from GMT-6 for an unknown reason. It is set to “Auto” time zone mode. It happened once or twice over the past month or two, but it’s happened for a few days in a row now. I have cleared the Android System cache (outlined here) as well as All Installed App Caches (here)
I did both of those yesterday, and the time zone was then correct (GMT-6). An hour ago it changed again to GMT. FWIW, it seems like it switches in the late morning (between 10 and noon). I’m pretty sure there have been times where it corrected itself after a few hours, but I don’t recall anything more specific.