HTTP proxy HTTPS? WebSocket connection?

[LazyYangi]

socket.io.js:4500 WebSocket connection to 'wss://sc.io.gypserver.com/socket.io/?EIO=4&transport=websocket&sid=agaNW-f_HfJgRxESAAEN' failed:

[darrachequesne]

The server does seem reachable:

$ curl -v "https://sc.io.gypserver.com/socket.io/?EIO=4&transport=polling"
0{"sid":"Mg_YFw66vy2wd6R6AAEk","upgrades":["websocket"],"pingInterval":25000,"pingTimeout":20000}

Are you using multiple Socket.IO servers?

Documentation:

• https://socket.io/docs/v4/troubleshooting-connection-issues/
• https://socket.io/docs/v4/using-multiple-nodes/