Same issue here, using Firefox on a Windows 10 Pro Dell laptop.  When volume on my computer controls is set to say 12, it's a comfortable volume.  When a new song starts, it comes in MUCH louder, as if volume jumps to 30 or so.  Click my computer volume controls and it still displays volume 12, even though sounding much louder than anything else would at that displayed volume level.  But then if I click on the volume slider close to where it shows, it jumps back down to reasonable volume.  It's like each new song that starts overrides the volume settings on my computer from wherever it is set to the middle of the slider.  Very annoying.  Makes me have to run Pandora from my phone app if I want to listen while working.  Almost worthless trying to make it run through a browser on my computer.  ... View more