To start, can you let us know the make and model of the device, operating system, and version of Spotify you're using?
Also, we'd like to get some more detailed info about what's going on. When Spotify Freezes, it's just for a few seconds and it continues to play, or do you have to close it in order to have it to work again?
Does this happen while playing an Specific album/playlist or is it random?
I have a Macbook Air (13-inch, Early 2015) with macOS High Sierra and I'm using the latest version of Spotify. The freezes were lasting 30-40 seconds and reappearing after a minute or so. They neither stopped the music from playing nor made me restart the app but they were frequent and they prevented me from using the app decently. The app was freezing whether I was listening to music or not. Today I reinstalled the app and it seems to be okay at the moment. Will let you know if I face the problem again.
Hardware acceleration should be at the very bottom of the Advanced Settings. Click the arrow next to your username > Settings > Show Advanced Settings > Compatibility, and turn off Hardware Acceleration there.
About the firewall, try making sure Spotify is set as an exeption to see if it helps.
Keep us posted.
“Music acts like a magic key, to which the most tightly closed heart opens.” ― Maria Augusta von Trapp