I have the same issue. Whenever I open Spotify and start playing a song, the sound stops. Then I try to download Spotify to MP3 with TunesKit Spotify Music Converter and then play the songs offline, it works.

I'm now playing the offline songs from Spotify. Just get a TunesKit Spotify Music Converter and download songs from Spotify. It's pretty easy to play everything on Spotify to Oculus home

Hey, I'm playing Apple Music on my phone, can this plays songs from Apple Music? Or I can download my songs with TunesKit Audio Converter and upload them to the visualizer, guess that'd be amazing.

They don't have a integration yet, but you can download Spotify songs with Tuneskit Spotify Music Converter and then play them on rift offline.