Magnifi Max faint channel

Maladon

Not the soundtrack, but background music sounds very faint. An example: At the very beginning of Iron Man when Back in Black starts playing. It sounds ok when coming from the radio, but when they start playing it loud, it sounds much fainter, almost like it is being played through a channel that I don't have a main speaker for. The closest post I have found that kind of describes the problem is this:

https://forum.polkaudio.com/discussion/184433/polk-magnifi-inconsistent-audio-level

It drives me nuts for some reason and if I can't find a solution, I'm selling it. Does anyone have any ideas? LG OLED TV and a 4k Apple TV. Thanks.