I am an experienced Firefox Add-On user. I have installed Firefox on a new build Windows (10) computer. Only 4 of my 8 installed Add-Ons will show on the Task Bar This is not a problem on my two other Windows machines that share the same Mozilla account for Bookmarks & Passwords. (Other machines are also 4K displays). I have uninstalled then reinstalled Firefox several times on the new machine, nothing seems to work. I suspect there is a simple fix, but it eludes me. Suggestions?