Issues on playing songs on Spotify

[Hamarth]

Greetings everyone,
I would like to share the issues I'm having right now with Spotify, in order to find a solution (also I would like to apologize for my english too, it might be confused).
Since yesterday (22/09/19), it's impossible to play certain songs on the desktop app (there is also issues with the album covers / playlist loading but that's not the main one). It seems random at first, since I can play some songs of one of my playlist. When I want to play a song, the album cover may appear, and the timer stay at 00:00 forever. 

1. I noticed that my Discord's profile wasn't showing the music I was listening to on Spotify.
2. I tried to disconnect / connect (on Discord app) to try to fix the problem.
3. It loaded the "please connect" page, used my facebook account to log in, and never got further than this (everytime I tried it loaded a blank page). I don't know if there is a link between those two, or if it's a consequence of my issue. 

I tried many things to fix it, as mentionned on the support, like:
 - Restating Spotify

 - Disconnect / Connect
 - Download Spotify 

None of them worked. I only remember, when logging in that my firewall may prevent Spotify working correctly, and it may need an update (but it wasn't on at this point, and it didn't needed an update).
Oh and it works on my phone, so I believe it's on my computer.

Screenshot 1: Issues with album covers / playlist loading & song forever stuck on 00:00 

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France
MacBook Air 2015

iOs X (10.10.5)