Foreground app loses focus(?) when Spotify starts a new song

[JSStaedtler]

On my Android Pixel 2XL I'll typically play Spotify in the background while using Google Maps navigation, but for the past few weeks I've found Maps will minimize to picture-in-picture mode whenever the track changes in Spotify. I can restore Maps to full screen, but it will just minimize again on the next track. It got so annoying that I turned the PIP feature off in Maps (although I want it to be on). I found that the same thing happens to the GPS Status app, so it seems Spotify is doing something to these apps to push them out of the foreground (I'm not even sure of the right terminology here}. Is this the result of some setting within Spotify, or have I stumbled upon some bug?