When I play a track on Spotify, within a second of playback, the volume reduces from a clear, loud, crisp sound to a quieter, muffled, dull sound. This happens on any track I select and it also happen when playback occurs through my device speakers, earphones, and bluetooth connectivity via a wireless speaker.

I have only just started listening to Spotify on my new Google Pixel 2 XL. I don't recall it happening on my iPhone 6 or Samsung Galaxy S7 Edge.

I have reinstalled Spotify and I have cleared the apps cache and data. I have looked at some of the settings to see if this solves the problem. For example, the problem continues when I toggle the 'Normalise volume' option or when I try a range of different equalizers.

My device is running the Oreo 8.1. operating system and I have the most updated version of Spotify. The dip in volume and sound quality is really baffling and is ruining the listening experience. I find the volume on Spotify to be very dull and quiet anyway but what is now noticeable is how much better the sound is during that first second of playback compared to how the music plays after that first second. 

Any help on this would be much appreciated.