It's a huge issue that has thousands of prior complaints. If you feel it's the bar or TV you could return those as defective but the complaints about conversation being drowned out or low is very common.

I take it you researched this so what I write next is the usual to try.

Set the TV to send only Stereo or PCM to the bar. Look around for any settings that sound like "Clear Voice" or similar. Test that out. I do NOT expect this to fix it as a lot of content is pretty bad when it comes to voice clarity.