I have the international D802 version and the "settings / tethering & networks / mobile networks / network mode" only shows 3 options, GSM/WCDMA; CDMA only; GSM only.
When I go into dialing *#*#4636#*#* or if I go into dialing 3845#*802# etc...to choose LTE/GSM/WCDMA! I can choose this mode and it works UNTIL I reboot, then it goes back to GSM/WCDMA!
Is there is anyway to make the LTE/GSM/WCDMA mode stick?!
In build.prop change ro.telephony.default_network=9 from 9 to 11!
I got LTE settings in mobile networks menu. And it sticks after a reboot!
Thanks to @ejerez for the info in Here!