MediaHandler goes into an infinite loop in Firefox with resistFingerprinting

Describe the bug

When the web app tries to start the camera and mic after being granted permissions on Firefox, they keep getting toggled on and off repeatedly forever, until I manually stop the process, by reloading the page, or in some other way.

The Web Console is spammed with this error log repeatedly until manual intervention:

Uncaught (in promise) DOMException: The fetching process for the media resource was aborted by the user agent at the user's request.

I use Arkenfox’s user.js, so it’s possible that some hardened preference is causing this. For example, CORS is being denied to Matrix Sentry, though I’m assuming that’s just analytics, and irrelevant to the functioning of the web app.

If that is the case, could you specify what needs to be changed? For the record, Jitsi and other web apps work fine with my setup.

To Reproduce

1. Enter a username and room name and join call (doesn’t matter which type).
2. Grant camera and/or mic permissions when asked.
3. Error occurs. Open Web Console to see error message spam.

Expected behavior

The camera and/or mic to work and for the call to go ahead.

Desktop (please complete the following information):

• OS: Windows 7
• Browser: Firefox 100

[robintown]

Nope, this is simply a bug on our end

[opusforlife2]

Thanks for the info.

For the record, Jitsi and other web apps work fine with my setup.

Is Element Call using some feature that these other apps don’t need? I just tested Jitsi again with the exact same setup, and everything works fine.