I bought a 75 inch TCL Series 6 Roku TV and a Klipsch Cinema 600 sound bar to go along with it. The sound bar is 5.1 as it has two wireless rears. I have it hooked up via eARC on the TV to ARC on the sound bar. TV speakers are off. I get true 5.1 DD sound when I watch Netflix, Amazon Prime or HBO Max when using the auto detect or DD setting on the TV, but other apps only come in stereo. Right signal on the right rear and bar and left signal on the left rear and bar. Even when using apps I know are broadcast in at least 5.1 DD. When I switch the TV audio settings to auto passthrough I only get stereo just like it would be if it were set to PCM, even on the Netflix and other apps I was getting 5.1 on. It just doesn't make sense. I have tried a different HDMI cable. I tried hooking it up with an optical cable. Nothing changes. When I watch a show on Netflix in 4K that I know is in DD 5.1 with the TV set to the auto passthrough setting I only get stereo through the rears and the Dolby Digital signal on the bar doesn't light up. Shouldn't auto passthrough just send whatever signal is being sent directly to the AVR or bar? I have a traditional 7.1 set up with another brand of TV and do not have this problem and that is one of the reasons I know what signal I am getting from certain apps because the Yamaha AVR tells me. I have updated software. Factory reset both the TV and the bar. Does anyone have any ideas other than the auto passthrough on this TV being bad? Any help or idea would be greatly appreciated. Other than this issue I am very pleased with the TV.