GitHub 无法读取远程仓库，port 443: Connection refused？

Question

~/.ssh/config 关于 GitHub 的配置如下：

Host github.com
    User luhuadong
    HostName ssh.github.com
    PreferredAuthentications publickey
    IdentityFile ~/.ssh/id_ed25519
    Port 443

之前一直可以用的，这几天突然就连接不了，fetch 和 push 都不行，如下：

$ git push origin main 
ssh: connect to host ssh.github.com port 443: Connection refused
fatal: 无法读取远程仓库。

请确认您有正确的访问权限并且仓库存在。

下面是测试通过 HTTPS 端口的 SSH 是否可行的结果：

$ ssh -vT [e-mail]
OpenSSH_8.2p1 Ubuntu-4ubuntu0.4, OpenSSL 1.1.1f  31 Mar 2020
debug1: Reading configuration data /home/rudy/.ssh/config
debug1: /home/rudy/.ssh/config line 15: Applying options for github.com
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files
debug1: /etc/ssh/ssh_config line 21: Applying options for *
debug1: Connecting to ssh.github.com [::1] port 443.
debug1: connect to address ::1 port 443: Connection refused
debug1: Connecting to ssh.github.com [127.0.0.1] port 443.
debug1: connect to address 127.0.0.1 port 443: Connection refused
ssh: connect to host ssh.github.com port 443: Connection refused

请问是哪里的问题呢？有其他小伙伴遇到吗？

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解决办法记录：https://getiot.tech/github/github-errata-port-443-connection-...