Go - Expected: HTTP-version, Received: ""

[ghotdog]

I’m on #IA4, writing it in Go. I see there are same topics for different languages, none of the solutions work here. I tried different versions of code (copy/pasted from code examples), none seems to pass the test.
When I execute the same curl command as test and run it myself, I get the correct response (see uploaded image), also in Chrome web console I can see the response, but for some reason it does not pass the codecrafters test. Any ideas?

package main

import (
	"fmt"
	"net"
	"os"
)

func main() {
	l, err := net.Listen("tcp", "0.0.0.0:4221")
	if err != nil {
		fmt.Println("Failed to bind to port 4221")
		os.Exit(1)
	}

	for {
		conn, err := l.Accept()
		if err != nil {
			fmt.Println("Error accepting connection: ", err.Error())
			os.Exit(1)
		}
		go handleConn(conn)
	}
}
func handleConn(conn net.Conn) {
	response := "HTTP/1.1 200 OK\r\n\r\n"
	fmt.Println("Writing response", response, []byte(response))
	_, err := conn.Write([]byte(response))
	if err != nil {
		fmt.Println("Failed to write response: ", err.Error())
		os.Exit(1)
	}
}