Whenever I go to a network with both ipv4 and ipv6, and try to access Spotify from Firefox on Ubuntu Linux (play.spotify.com), I get this message after a short while (1-3 mintes):
"Can't connect to Spotify. Trying again now..."
If I go to a network that only has ipv4, or if I stay on the same ipv4+6 network but DISABLE ipv6 on my laptop, then Firefox plays fine with Spotify.
ipv6 is the problem.
Please fix it.