Hello. My device is a Motorola Z3 Play. Running Spotify 184.108.40.206 Android version.
An example to reproduce the issue:
While listening music, you receive an audio msg from WhatsApp. You pause Spotify, go to WhatsApp and play the audio. In the middle of listening that audio Spotify will start playing again. You can pause it again and again and it will start playing when you are listening to the audio msg.