Firefox for Android 68.0 - WebSocket is broken when using 'mobile data' (ok using WiFi)
When initiating a Web Socket request, (RFC 6455), the client is supposed to send the following headers:
Connection: upgrade Upgrade: websocket Sec-WebSocket-Key: ... Sec-WebSocket-Version: ... Sec-WebSocket-Extensions: ...
When connecting to the server over WiFi Firefox does this.
When connecting to the server over 'mobile data' Firefox sends different headers: the Connection header has value 'keep-alive' and the Upgrade header is absent altogether. The Sec-WebSocket-xxx headers are still present.
Of course Chrome works perfectly.
Additional System Details
- User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0