the mystery continues
Thanks for your reply. I have an LG "smart" TV, about 2-3 yrs old. The internal sound has no interference with the sound bar, just turn it to zero to get the sound bar full effect. If you turn up the internal sound, you just hear two different sounds, whose timings are slightly different. This AM I tried it again and it worked perfectly fine! So I'm left with the fact that I have no idea why it did not work yesterday PM and seems to be fine again today. I did not change any settings.