Spotify with DNS over TLS

[edz]

I have been using DNS over TLS with Cloudflare IPv4 and IPv6 servers successfully for sometime.

I recently noticed that the Spot Apple TV and iOS apps reported 'Connecting' or 'No internet connection'.  I validated that none of the Unbound blocklists were blocking the Spotify servers and the moment I switched to an external DNS, Spotify would work.

Narrowing it down, I then removed all the DNS over TLS servers and only enabled 8.8.8.8 port 853.  This allowed Spotify to connect with no issues but the moment I re-added the Cloudflare IPs (both IPv4 and IPv6) Spotify wasn't happy. 

Not sure if the server list is used in a round robin fashion.  Does anyone know why Spotify is only playing nicely with Google's DNS when using DNS over TLS?

[koushun]

If you disable all other DNS servers except Cloudflare's, what happens then - is your OPNsense firewall able to ping any of the spotify's servers? Then the problem might be Cloudflare.

Why, you say? Do not know.

I had the same issue when using Quad9 (not Spotify, it was just another random service); so I just dropped using them. I use a combination of 5-6 of those I found here: https://dnsprivacy.org/public_resolvers/