Phaser sounds don't play (firefox 69.0, archlinux)

Hello there. I’m new to Phaser, and this is my first post in this forum.
I can’t get Phaser sounds to play in my browser.
I’ve tried to run the examples in Phaser.io, and I’ve tried playing a game made with Phaser (Rogue Fable III). Everything else works fine, but the sounds just don’t play. Firefox doesn’t even show the sound icon in the tab.
My partner is also using firefox 69.0 on archlinux and the sounds work fine on his machine, but they don’t work on mine. I can’t figure out why, and I would love to hear some suggestions.
We’re also trying to make our own game, so I made some tests with that. I can play the music files in the browser, but I can’t hear the music inside the game. Any ideas?