Pulse Eight CEC Not Working on LibreElec

I have an Asus Chromebox running Kodi 17 with LE V7.90. I bought a Pulse Eight CEC adapter but cannot get it to work and wondered if someone could point out where i am going wrong or what might be my problem, assuming this should work?

I have my TV into a sony Sound bar which goes into a HDMI switch, then into my Chromebox. I powered down the Chromebox, plugged in my CEC adapter then power on and get nothing on screen, no signal. I’ve tried this plugging in the adapter to the usb before connecting the HDMI too. Also, the soundbar for some reason switches on and will be set to Optical input instead of HDMI. Do i need to configure anything?

I tried this a few weeks ago and actually got into Kodi and when configuring the CEC settings, it somehow completed wrecked my soundbar to the point where it would not display any video and i had to do a hard reset on it.

Is there any kind of basic setup guide of how to plug in and configure this that i could refer to?