iOS app skips to next song when streaming on 3G/bluetooth

[blackh0lesun]

I bought a new head unit for my car, Pioneer DEH-X8700BT. 

When I stream Spotify over 3G via bluetooth to the Pioneer unit, the app automatically skips to the next song. Sometimes after a minute, sometimes after five seconds. I reinstalled the iOS app, streamed one album, it played fine. The next day skipping began again. All streaming/playback options in the iOS app set to auto/default. Crossfade and normalize switched off.

The issue does not occur when playing back offline content in Spotify.

It never happens when using Tidal app, even when 3G coverage is horrible.