As per this issue I reported a [https://support.mozilla.org/en-US/questions/1309000 while back], I was experiencing odd issue with automatic redirect to HTTPS for some private development sites. I finally found a fix for the issue. The problem appears to be with DuckDuckGo Privacy Essentials Extension which apparently *may automatically redirect to the http site. In order to prevent this, I added my development sites to 'Unprotected Sites' and this prevented DuckDuckGo from doing the automatic redirect to https. * - Odd thing is that I had multiple domains pointing to the same web instance and only one of the domains was having this issue with the DDG extension. Both were going to the same IP through a HTTP proxy. The proxy and web server were not the issue. This symptom points to an maybe an issue in Firefox.... In summary, be wary of odd redirects and the DuckDuckGo Privacy Essentials extension if you are doing web development work.