Solution

If you need HTTPS to protect your privacy on all pages of AskUbuntu, install the HTTPS Everywhere browser extension and it will modify all requests by replacing http: with https:.

Explanation

This is a weakness of StackExchange and should be corrected. They might need to invest money on better hardware and in software engineering to support the huge number of TLS 1.2 connections, otherwise some visitors may experience timeout or certificate errors.

HTTPS Everywhere has a special rule for AskUbuntu and you will not have connection problems. Your browser will show a green lock, click on it to see: 128 bit TLS 1.2 encryption from DigiCert Inc..

Suggestion

If you use Mozilla Firefox (or Iceweasel) and the privacy is a huge priority of your LAN, visit about:config from your address bar and search for the option security.tls.version.min. Insert a higher number to prevent some HTTPS degradation attacks.