What Should Network Mode Be?

This should usually be on Auto Mode unless you know you're never going to roam or move to another network or area.
 
Mine does not have a choice for "Auto". It is set to "Global".
Sounds like you are VZW, set it to LTE/CDMA. Global works but it uses all the radios, LTE does not. This is how Vzw explained it to me. Use global when traveling out of the territory. I have tried both and had better results on LTE. I am on the east coast.