I just got both and the soundbar seemed to link up fine to another TV that I have but when I connected the HDMI cable from the soundbar ARC port to the TV's arc port and tried using the YouTube app on the TV it wasn't playing anything over the soundbar no matter what setting I seemed to put it on. Not really sure what I am doing wrong. I guess I don't know enough about the way ARC actually works. I know it allows audio and video to pass through but does the TV need to be on HDMI 1 (the ARC HDMI port), what setting does the sound bar need to be put on? No idea how to turn on CEC on my TV either.
Refer to your owner's manuals (TV and soundbar). HDMI-CTL needs to be enabled on both. Sometimes there is a separate setting for ARC. Usually you also have to change the speaker settings on the TV to "external". The HDMI cable needs to be rated as high-speed. Sometimes just trying a different cable fixes an issue, assuming you have all your settings correct.