That's why I dug up Firefox 61.0.1 and I'm using it right now - 61 has the option to disable browser updates and it doesn't have the latest content blocking crap. Plus, I've disabled its ability to check addons against its black list. A few months ago Mozilla waged a war against all adblockers and addons like Ghostery (even removed all these addons from their addon website) but I found a way to suppress that war, so that I can continue to use an adblocker.Appears to be fixed
firefox 'updated' and introduced all sorts of crap to do with content blocking, data etc etc.