I recently had to update my iOS to the new 11.3 version. (BTW, iOS11 sucks).
Now every time I use Spotify connect (with my amazon tap) I can’t control my device volume anymore or change the tracks with control center.
Back when I had iOS10 running, I would change the volume on my iPhone when at the Spotify app and it would recognize my amazon tap and change the volume. If I was using some other app, it would only change the volume for that app. I.e.
 iOS10 > Spotify playing on Amazon Tap and Spotify Connect on my iPhone > Change iPhone volume with Spotify opened > Change Tap volume
 iOS10 > Spotify playing on Amazon Tap and Spotify Connect on my iPhone > Change iPhone volume on home screen > Keeps Tap volume and changes iPhone volume
 iOS11 > Spotify playing on Amazon Tap and Spotify Connect on my iPhone > Change iPhone volume with Spotify opened > It won’t change Tap volume but changes iPhone’s speaker volume.
Furthermore I could change tracks on my control center or locked screen. But now on iOS11 everytime I connect my Spotify via SpotifyConnect, the tracks playing at Spotify will fade from the control center and lock screen to give place for other apps’ tracks even if I’m not playing anything at the time! I.e.
 Playing Spotify on my iPhone iOS11 > I can skip tracks and change volume on control center
 Playing Spotify on Amazon Tap with Spotify Connect on iPhone iOS11 > Control center won’t display musics playing at my Tap, but rather the tracks at my phone, even if I’m playing none at the moment.
 Playing Spotify on Amazon Tap with Spotify Connect on iPhone iOS10 > Always display Spotify tracks on control center and lock screen.
Back on iOS10 everything worked fine. It was like the software knew which device I wish to control based on the current app at my screen. What’s up with Spotify Connect on iOS11?!
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iPhone 8 Plus