NVRAM doesn't reset volume level

Hi there.

Recently, my MBP retina 2014 started to decrease volume level on headphones, few seconds after i connect them.

You can really hear the volume decreases by 50%.

I tried nvram, and it didn't help.

I'm using the Apple EarPods that came with the iPhone.

Most of the time it happens on the internet and not in iTunes.

Thanks!