I have Nokia 43inch UHD Android TV. Recently I used an app pre-installed "Audio Connect" on my TV and since then audio output of TV is increased to many folds. Even using TV audio output at 5% (volume bar), it sounds unbearable to hear. I used that app to connect my phone to TV via Bluetooth for listening songs and now it caused audio boost.

I tried resetting all the settings (including audio and whole TV reset) but still it didn't fixed up the problem. I don't know what caused the problem and also I recently upgraded to new Android update. Is new update is the cause because earlier using same app gave no problem? Or is it a hardware problem now cause I reset any settings I can find and problem still exist? Any ideas?