At about 6:00pm Firefox released an update of Firefox 19.0.2. In this version i tried to recreate the bug but was unsuccessful. I recommend you update and see if it continues.

Clear the cache and the cookies from sites that cause problems.

"Clear the Cache":

• Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

• Tools > Options > Privacy > Cookies: "Show Cookies"

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe mode start window or otherwise make changes.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

I went ahead and updated to most recent Firefox, and problem still persists. However, it seems that I mischaracterized the bug in my original description, and it seems to occur when I enable safety mode on YouTube. For example, I type https://www.youtube.com into my address bar, and then once on the site enable safety mode upon which I get www.youtube.com.

Thanks for taking a look at this.

Thanks for the suggestion.

I cleared cache and cookies, tried out safe mode, and the issue still persists, i.e., when I enable safety mode on youtube I lose the https connection.

Does this mean the issue is more likely belonging to YouTube rather than my browser?

(I've also run malwarebytes, and no issues detected by it.)