Xperia Z5 :: Spotify Stops After Each Song

I recently switched from iPhone to Xperia z5 compact, so I don't know if this is an issue which already affected previous models.

Basically, I usually listen to music using bluetooth headphones. However, this is not always possible and I sometimes need to use devices with a cable.

Now, I've been mainly using apps like Spotify and Deezer to listen to my music and whenever I am on one of these with cable headphones or if I plug a cable to connect my phone to my car speakers, annoying things happen. In fact, in these situations, I can only play one song, after which the music stops and I have unlock the phone, access the app and start the new one from the app itself (it doesn't work from the lock screen or the notification centre). This problem is affecting only third parties apps apparently, or Deezer and Spotify. In fact, if I use the Sony Music app, cable headphones work fine.