Billion UK Forum

I have a hostname registered for my home ISP IP address, which has an enhanced DNS service, which enables me to get an SSL certificate from a trusted source for my home IP's hostname. I have a web server configured behind my Billion router, which routes HTTP and HTTPS traffic directed to my home hostname to it. This has been working fine for a few months now. However, this week I started getting connection denials on all browsers that said the CA authority was untrusted, or words to that effect. I searched Google and one suggestion was to reboot your router, which I did. The denials then went away.

Therefore, what happened on the Billion router to cause this issue?