I couldn't tell you when it actually started, but I noticed it about 2 weeks ago. It's impossible to predict e.g. I open 4 identical tabs to my youtube subs page and maybe one loads. The pages work 100% of the time in Chrome, but I'd really like to just fix what's wrong in Firefox. See attached for how the tabs look and how a broken youtube subs page will look. I am updated to the latest version. Thanks in advance.