I'm running Win 10, and it's 100% up to date, as is Firefox. Like Old Iron said, when it updated it went to pot. Some pics won't load, parts of web pages are missing, smileys won't work some places and others they will, even going from one thread to another on a board can take a few minutes of watching the two balls bouncing, kinda like the old dial up days. I've tried updating FF, but it's up to date. FF works a little better on my phone and android tablet, still slow, but that could just be connection issues.
Chrome is working superfast here on the pc. One page to another in milliseconds. I just prefer Firefox, I've used it ever since I got DSL and got away from AOL dialup. Every other browser just feels off a bit, FF is, or was , home. No more though.
My computer updates Windows every Tuesday. No telling how many times it starts and restarts installing updates every week or so. Every once in a while it will not install one and I have to manually do it, but that's pretty rare. I try to keep a check on it.
I'm glad Old Iron reported he's having the same problem. At least now I don't think it's on my end, I think it's in their {FF} code somewhere.