Originally Posted by coyttl
Starting about .. oh, 3 or 4 months ago, I've noticed my phone dropping data, OR, getting stuck on 'E' or 'G' symbols, even in areas that have LTE. Every time I notice this, I go into APN Settings, and I find that the selected APN has changed. (Usually from 'T-Mobile US LTE' to just 'T-Mobile US'..)
I don't have any APN apps or anything, but have been running AOSP v4.3 (then v4.4) since about the same time this started.
Any ideas on what to check? Am I going crazy? (Is my phone going crazy?)
You could delete the APN's that you don't want it to switch to. Just leave yourself with the one you want, and it shouldn't be able to change.
Now that MIGHT cause it to switch to nothing, leaving the phone without any connection. But if that happens a revert to the nandroid backup you make before trying this would fix it, at least back to what you have now.