Insufficient capacity modal on first connexion on Firefox + proxy

[MarcWadai]

Steps to reproduce

1. Where are you starting? What can you see?
   On some PC configured with network restrictions (proxy, vpn, firewall etc?, not sure what is causing the issue). The first connexion using element-web pop the "Insufficient capacity" modal. The other participant can see the new member with waiting for media avatar.
   Closing the call, and restarting/joining works withouth the insufficient capacity modal.

Looking at the logs, we can see it is the websocket connection to the livekit that is failing :

Lifecycle] Connecting & publishing index-ByQHsvE1.js:2:1792735
[Lifecycle] Connecting to livekit room wss://livekit.fr ... index-ByQHsvE1.js:2:1792735
[MatrixAudioRenderer] All audio tracks have a matching matrix call member identity. index-ByQHsvE1.js:2:1792735
silence detected on local audio track 
Object { room: undefined, roomID: undefined, participant: undefined, pID: undefined, trackID: undefined, source: "microphone", muted: false, enabled: true, kind: "audio", streamID: "{d9d1bca6-7ff4-4988-aaea-26f9e32e58ec}", … }
index-ByQHsvE1.js:2:1792735
Firefox can’t establish a connection to the server at wss://livekit.fr/rtc?access_token=token.testmcmllcy1iZXRhLmdvdXYuZnI6YWdlbnQuZGludW0udGNoYXAuZ291di5mcjpCRllaVEZBQlNWIiwidmlkZW8iOnsiY2FuUHVibGlzaCI6dHJ1ZSwiY2FuU3Vic2NyaWJlIjp0cnVlLCJyb29tIjoiIUpRZWVQTXF0ZHRHdklEY3NFQTphZ2VudC5kaW51bS50Y2hhcC5nb3V2LmZyIiwicm9vbUNyZWF0ZSI6dHJ1ZSwicm9vbUpvaW4iOnRydWV9fQ.nRnqYEps6nqxTU72-AhZxD943QeybOK3MgLkZbJb3j0&auto_subscribe=1&sdk=js&version=2.15.7&protocol=16&adaptive_stream=1. index-ByQHsvE1.js:2:1109599
websocket closed 
Object { room: undefined, roomID: undefined, participant: undefined, pID: undefined, reason: "", code: 1006, wasClean: false, state: 4 }

Outcome

What did you expect?

To start/join a call directly without seing the "Insufficient capacity" modal for the first connexion

What happened instead?

I see the "Insufficient capacity" modal, needs to close the call and retry for it to work

Operating system

Windows

Browser information

Firefox 147.0.2

URL for webapp

using element call 0.16.3 but also failing with 0.17.0

Will you send logs?

No