Sound gets very low and shallow

[JuliusKoroll]

My music-sound gets really low and thin after 3min of listening. Its in every audio-player. After replugging the headphones it works again for some minutes. How can I help fixing this?

[JuliusKoroll]

I tried a restart, closing all apps. Its in every music-app. Headphones are Sennheiser Momentum 2.0 Android. 

And YES, I tried in Safe Mode and it works great.

[Sensination]

I think this might be beacuse of the requirement of European Union that after listening to music on high volume, the phone has to lower the volume down and display a warning that you might damage your ears.

Do you get a message on the screen when the volume goes down?

Can you put the volume back up after it goes down?