Is this a bug report?

Yes

Steps to reproduce

1. Setup the project as written in the readme
2. Create an endpoint to check if the request succeeds (mine is on https://webhook.site)
3. Execute a request with no body (using postman) => succeeds
4. Execute the same request with a body (using postman) => timeout/ no response

The request:
http://127.0.0.1/proxy/MY-WEBHOOK-IDENTIFIER

Expected behavior

forward http://127.0.0.1/proxy/MY-WEBHOOK-IDENTIFIER to https://webhook.site/MY-WEBHOOK-IDENTIFIER no matter what content:

No timeout when requesting on http://127.0.0.1/proxy/MY-WEBHOOK-IDENTIFIER with a content
No timeout when requesting on http://127.0.0.1/proxy/MY-WEBHOOK-IDENTIFIER with no content
No timeout when requesting on https://webhook.site/MY-WEBHOOK-IDENTIFIER with or without content

Actual behavior

Timeout when requesting on http://127.0.0.1/proxy/MY-WEBHOOK-IDENTIFIER with a content
No timeout when requesting on http://127.0.0.1/proxy/MY-WEBHOOK-IDENTIFIER with no content
No timeout when requesting on https://webhook.site/MY-WEBHOOK-IDENTIFIER with or without content

Setup

app.use("/proxy", createProxyMiddleware({ target: "https://webhook.site", pathRewrite: { ["^/proxy"]: "" }, logLevel: "debug", changeOrigin: true }));

• http-proxy-middleware: 1.0.3
• http-proxy-middleware configuration: logLevel=debug, changeOrigin=true, pathRewrite={ ["^/proxy"]: "" }
• server: express + 4.16.3

client info

OS: Linux Mint 19.3 "Tricia"
User-Agent: PostmanRuntime/7.24.0

target server info

Webhook.site: A free web server to mirror incoming requests