I usually have Firefox open for 8 hours a day (open Firefox in the morning and close it in the afternoon). About once a week I'll notice that at some point during the day… (read more)
I usually have Firefox open for 8 hours a day (open Firefox in the morning and close it in the afternoon). About once a week I'll notice that at some point during the day Firefox will just stop loading new websites. Existing sites will continue to function, and requests to those existing domains work. But new sites, that I didn't already have open, won't load at all; the tab will just sit there, thinking indefinitely (no errors).
When it does this I will try microsoft.com or google.com to check and make sure it isn't just the site, but those won't load either. I'll try it with a Private Window as well to the same effect (private window has no extensions enabled). Chrome/Edge still work fine during this. In order to get Firefox working again, I have to close Firefox and then usually force quit the process instances (or wait a long time for it to reopen on its own). Once reopened everything is back to normal and all sites load as normal.
I think this happens when Firefox loads a new update in the background. I've noticed on more than one occasion this behavior has coincided with a new Firefox version. In fact it just did it again (prompting this post) and when I got Firefox back open again it had a new update tab displayed. So I'm fairly sure it is the background updates causing this.
This behavior has been happening for a very long time. At least 6 months. Across many Firefox updates.
I have a separate Firefox profile that I load using a separate shortcut (with the -P property). When this behavior happens it often impacts both instances of Firefox. Not sure if this bug is related to having multiple profiles or not.
Windows 10 64-bit