Unix socket in HTTPS causes cert error even when `rejectUnauthorized` is off

Version: 6.10.1
Platform:
Subsystem:

This code runs well:

let options = {
    key: fs.readFileSync("key.pem"),
    cert: fs.readFileSync("cert.pem")
};

https.createServer(options, (req, res) => {
    console.log("Request received");
    res.writeHead(200);
    res.end("hello world\n");
}).listen(50000, "127.0.0.1");
console.log("HTTPS server started.");

setTimeout(() => {
    https.request({
        host: "127.0.0.1",
        port: 50000,
        rejectUnauthorized: false
    }).end();
}, 1000);

But if I use Unix socket, then it will fail, saying self signed cert error:

let options = {
    key: fs.readFileSync("key.pem"),
    cert: fs.readFileSync("cert.pem")
};

https.createServer(options, (req, res) => {
    console.log("Request received");
    res.writeHead(200);
    res.end("hello world\n");
}).listen("/Users/zzz/test-unix-socket/socket.sock");
console.log("HTTPS server started.");

setTimeout(() => {
    https.request({
        socketPath: "/Users/zzz/test-unix-socket/socket.sock",
        rejectUnauthorized: false
    }).end();
}, 1000);

key.pem and cert.pem is a self-signed certificate generated using OpenSSL:

openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 7300 -nodes

Is this a bug, or am I missing something?