sometime "WebSocket is closed before the connection is established" when proxy for websocket

[quicklearning123]

yarn why http-proxy-middleware OR npm ls http-proxy-middleware output (mask private folder names with *****)

── [email protected]

• [X] I understand project setup issues should be asked on StackOverflow or in GitHub Discussions.
• [ ] I updated to latest http-proxy-middleware.

Describe the bug (be clear and concise)

I user eggjs with http-proxy-middleware, and add a proxy for websocket request. But I get a error "WebSocket is closed before the connection is established" sometime.

Step-by-step reproduction instructions

I have no idea about how to get a reproduction.

Expected behavior (be clear and concise)

send and recv successfully every time

What http-proxy-middleware configuration are you using?

ws:true

What OS/version and node/version are you seeing the problem?

node:14.7
mac os

Additional context (optional)

Everything goes well before add the proxy of websocket

No response

[quicklearning123]

Is there anyone know the reason

[tinystorm]

what's your mac os version？