How can I change my LG G2 network mode to 3G only if the settings are locked?

[AC Question]

LG G2 Network Mode Locked

Hey All,

So I'm trying to change my network mode to a 3G only mode but for some reason the setting is locked for me.

What I have done so far is go to Settings--> Tethering and Networks-> Mobile Networks then I would click on network mode but for me it shows up as grayed out and unavailable.

I've also tried entering #*#*4636*#*# and going to phone information but when I do I get a note saying "This application does not work on this device".

So ideas, tips, tricks?

Thanks everyone