Thanks everyone for the suggestion. I paired the speakers to a beosound moment and guess what? the BL20’s sound awesome.
It’s not my imagination or a placebo effect because I can hear stuff rattling and shaking in the room. I immediately reset the Avant NG ( reinstall TV) but unfortunately that didn’t help.
For here I think it’s either the TV is doing something really nasty or I just need to live with it and use the internal speakers. I’ll keep the BL20’s for music only on BS moment.