I am having the same issue you have described with CarPlay on my Abarth 595. The music plays for some time and then the audio cuts and then comes back again and then goes silent. It feels like when you are listening to the radio and then drive into a tunnel, with static and white noise as well.
I have tried to reset the Abarth unit to factory settings and it didn’t do it. Tried to update iOS but it was the same.
Bluetooth streaming/connection works fine so I can still listen to Spotify, but I want to do it with CarPlay!
I had the same problem with Samsung galaxy. The songs would play but no sound would come out. I opened Youtube to see if it was every audio/video. As soon as the Youtube video started playing, the music from Spotify played too. I just quit Youtube and the music on Spotify just continued normally.