I have a Sony UBP X800 4K DVD player, a LG SJ8 Sound bar and a LG OLED TV 55C8. I connect the DVD player to HDMI In on the Sound bar and HDMI Out on Sound bar to HDMI ARC (2) on the TV. I get no signal, though the advice on here is to connect them all this way using HDMI cables for the best sound. Any suggestions please?