I have as well the same issue.
I own a LG55UF860 for few days and can't set it up correctly.
I have a Denon AVR, HDMI monitor1 ARC output connected to TV HDMI2-ARC.
A Raspberry Pi2 running Kodi connected to AVR HDMI5 (Media player).
From the TV remote, I can control directly AVR volume, mute, programs and through the virtual (on screen) remote, AVR input.
In the connect I can see Home Theatre and Home Theater (Kodi) but no control at all.
In All Inputs: Home Theatre I have
- DENON, AVR-2313, Unknown
- SIMPLINK Supported
- Universal Control Configured for AVR-2313
However I can't control anything to RPi/Kodi.
BTW, is it possible to SSH LG TV?
So, I'll try to find out and let you know in case.