sudo apt-get update连接失败及无法安装软件包问题求助

我这几周运行sudo apt-get update时一直遇到几个错误，到今天连sudo apt install都没法正常用了。我在网上搜了好多解决办法试了都没用，实在没辙了，希望有人能帮我看看问题出在哪，提前谢谢大家的帮忙！

运行apt-get update返回的错误： #

Err:2 http://archive.ubuntu.com/ubuntu jammy InRelease
Connection failed [IP: 185.125.190.39 80]

Err:3 http://archive.ubuntu.com/ubuntu jammy-updates InRelease
Connection failed [IP: 91.189.91.82 80]

Err:4 http://archive.ubuntu.com/ubuntu jammy-backports InRelease
Connection failed [IP: 91.189.91.81 80]

Err:5 http://archive.ubuntu.com/ubuntu jammy-security InRelease
Connection failed [IP: 91.189.91.83 80]

Reading package lists... Done

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/jammy/InRelease  Connection failed [IP: 185.125.190.39 80]
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/jammy-updates/InRelease  Connection failed [IP: 91.189.91.82 80]
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/jammy-backports/InRelease  Connection failed [IP: 91.189.91.81 80]
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/jammy-security/InRelease  Connection failed [IP: 91.189.91.83 80]
W: Some index files failed to download. They have been ignored, or old ones used instead.

运行sudo apt install的错误示例（以安装openconnect为例）： #

Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
E: Unable to locate package openconnect

备注：内容来源于stack exchange，提问作者Siromenthe