Your user agent shows that you run Firefox in compatibility mode for Windows 98 (NT 4.10).

• User Agent: Mozilla/5.0 (Windows NT 4.10; rv:47.0) Gecko/20100101 Firefox/47.0

Check that you do not run Firefox in compatibility mode. You can open the Properties of the Firefox desktop shortcut via the right-click context menu and check the "Compatibility" tab. Make sure that all items are deselected in the "Compatibility" tab of the Properties window.

I would try this if I had a shortcut for Firefox on screen but I don't. Any other suggestion? Thank You