This is more a possible solution to a “Your connection is not secure” issue.
I have been plagued with this since I put IceDragon on my shiny new PC.
I googled the cause and solutions - all to no avail - although in other circumstances they possibly do work.
In my case I managed to narrow it down to the use of VSO’s Downloader Video and Streaming software.
There is an option (new to VSO Downloader) named “HTTPS/SSL” with this installed and the program running I could not even get Google let alone any other site.
After experimenting I uninstalled Downloader - re-installed it, omitted the “HTTPS/SSL” element - NO ISSUES!
A case of buyer beware.
The website of VSO Downloader - “http://www.vso-software.fr”
I hope this is of some use to someone.