Using iTunes or Spotify to play music through bluetooth headphones. While the music is playing, I watch a YouTube video in Safari. When the video ends, the music is muted. I can see in the music app that it is still playing, just muted.
This only happens when using Bluetooth audio. Built-in speakers behave as expected.
This only started happening since I upgraded to High Sierra.
Macbook Pro OSX High Sierra 10.13.2 (17C88) Bose Wireless SoundSport headphones