I know this has come up many times before, I've read the solutions like this: https://support.mozilla.org/en-US/questions/1019210 But its old. There is also HSTS which Im not sure how that works and frankly, as a user I don't care. We use internal websites on a company intranet domain. For example, a simple webpage to show the status of an application. I had to enable apache and made its config, so I know for a fact the site itself is not redirecting to https (other browsers aren't redirecting). Firefox insists on changing my address bar to https. When I use tcpdump or check the firewall, I dont even see port 80 traffic, firefox doesnt even try. I tried the above, I also: - disabled addons (which I know dont redirect but to be sure) - erased the relevant history - deleted HSTS config file from my Mozilla profile - tried opening in a private window The site above is an example, it happens with other sites too. Sometimes, it works for a while and then it stops. Sometimes, I find another site entry in the HSTS file, remove it and try again. Sometimes it works, sometimes it doesn't. I'm at a loss what to try next. When I completely erase and start a new profile, without sync or addons, it might work but only for a short while. This isn't an option because literally, the only reason I still use firefox is because sync works reasonably well, across all devices, including most settings and addons. I hope someone can help me fix this, I'd appreciate it!