uBlock Origin seems to interfere with ability to connect to the hubs.mozilla.com ICE server

[misslivirose]

Description
uBlock Origin appears to interfere with the ability to connect to the hubs.mozilla.com ICE servers, resulting in not being able to hear anyone in the room when the add-on is added to Firefox. It is possible that this is unique to the setup that I have, but we do hear reports that people occasionally have ICE failures so it's also a possibility that others might hit this.

To Reproduce
Steps to reproduce the behavior:
Client A, using a different browser or computer to connect to a room

1. Connect to a room on hubs.mozilla.com and enter the room

Client B, using Firefox

1. In Firefox, connect to the Hubs room that Client A is in
2. Confirm in about:config that media.peerconnection.ice.no_host is set to false (the default setting) and that there are no ICE errors
3. From the add-on store, add uBlock origin to Firefox
4. Restart Firefox
5. Attempt to connect to the Hubs room on hubs.mozilla.com where Client A is
6. Observe that in about:config, media.peerconnection.ice.no_host is now set to true.

Additional information
At one point in the past, I had set the uBlock Origin preference 'Prevent WebRTC from leaking local IP addresses` to true, but this happens for me without enabling that setting as well.

This appears to reset media.peerconnection.ice.no_host to true each time the browser fully restarts. If I change it back to the default false value, Hubs works normally the rest of the time.

This does not appear to happen with Hubs Cloud deployments or on dev.reticulum

It does not seem to reproduce if I am the first person to enter the room

Hardware

• Device: Desktop
• OS: Windows 10
• Browser: Firefox (stable)

┆Issue is synchronized with this Jira Task

[brianpeiris]

See also this older related issue #420

[Softvision-GeluHaiduc]

I tried to reproduce the issue using Firefox 84.0 on Windows 10 but didn’t manage to.
I followed the steps but even when I set media.peerconnection.ice.no_host to true manually everything worked as expected.
Is there anyting else I could try?

[gorhill]

uBO will affect media.peerconnection.ice.no_host only when the setting "Prevent WebRTC from leaking local IP addresses" is checked. It is unchecked by default. I am not able to reproduce as per repro steps.

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@brianpeiris The issue you referenced was fixed in uBO last year by using a more relax mode, which was by then supported in Firefox.