Comment 9 for bug 2003851

I suggest adding a parameter or setting Timeout=120 in default settings.

apt -o Acquire::http::Timeout=120 update

https://askubuntu.com/questions/141513/how-to-lower-wait-time-for-repository-updates
added Acquire::http::Timeout "120"; in file apt.conf or /etc/apt/apt.conf.d/99timeout