I have an LG Oled TV with a Humax Freesat box, Sonos Gen 2 playbar, sub & 2 surrounds, this last week, I have had to turn the Humax sound virtually full power to get a decent sound, the TV itself & any music apps I use are fine are still fine, the sound bar on my mobile through Sonos app is on 95 when I turn the remote up for the Humax. I have turned off & taken plugs out for all, but is making no difference, also I unplugged the cables on the back of the Humax box to see if that would help.