XLR mic connected to audio interface doesn't work in Firefox
I have a Rode XLR mic connected to an Audient ID44 audio interface connected with USB to my Macbook Pro M3. This microphone works fine in other apps like Chrome and QuickTime, but it doesn't work in Firefox.
When I select the microphone in something like https://mictests.com/ or Google Meet there's simply no audio coming out. If I select a USB microphone (e.g. my Logitech webcam's) it works fine.
Something I noticed that in Chrome the https://mictests.com/ website detects 1 audio channel, whereas in Firefox it detects 20.
Here is a video of me first using Firefox, and then Chrome: https://share.cleanshot.com/DvYgbtkM.
Is anyone able to help me? I'm happy to provide any other information.