Hi. I think I'm in the same boat as you.
I got the same bar. I try the optical cable. The sound is fine. Then I read that hdmi have more bandwidth for the Dolby. I try to set up the cec on. I follow the steps as in the manual.
The bar shows up on one of the speaker options as a receiver.
I select it. There is not sound. But there is sound using the optical.
The TV is a Samsung 48j6300.
Did you figure out?