Spotify Connect not working from my Mac but working from my iPhone

[user-removed]

Hello,

I just bought a Premium subscription for Spotify but I ran into a problem :

I use a Marantz M-CR511 to stream my music wirelessly, I can stream with AirPlay from both my Mac and my iPhone without problem but I can only use Spotify Connect from my iPhone, Spotify on my Mac doesn't see the Marantz (which support Spotify Connect).

I've searched on the internet but can't really find an anwser.
Could someone help me please?

[user-removed]

I just saw that actually from my iPhone, the Marantz shows up as an "Airplay device", so it's not using Spotify Connect either. As a result, when I play music from my iPhone to my Marantz and I see the Spotify app on my Mac, it shows that I'm currently playing music from my iPhone.