To me you have a choice here. The product sounds defective so back it goes.
Or call up the maker to see if they have new firmware or ideas on settings.
I have a soundbar and the audio fades in and out. It will go from quite to my normal volume setting. The sound will not stay at one level the sound will just drop out and become quite. It is connected by TOSLINK everything new and it is connected to my tv. When I say it fades its like someone changed to volume to a lower level and the back up. Could this be the sound bar or interference or what? When I plugged it in to my tv sound came on the tv and sound bar I just muted th tv.