-UE settings & info
-Pref mode set
You may need to reboot. This worked for me on NC2 with a MetroPCS sim. If it fails then double check your APN. You may also try to factory reset the phone with your Sim inside. When you do a clean install you get more options under Network Mode in settings.
If this doesnt work I'm think I'm done with the Note 3 for now. All of the deeper articles are telling me that the Note 3 cant do 4G LTE. Something about the chipset being incompatible.
I finally got my phone to root and actually access this menu at the very least. However, upon following these instructions I still have 3G/H+ showing up over my data icon.
I may try a factory reset with the SIM in like you suggested when I have a little more time. More to come.