Hello, Sadly numeric keys issue is a Firefox bug that I reported some time ago: https://bugzilla.mozilla.org/show_bug.cgi?id=1424708
You can up-vote it to get it more attention - so far it has low priority P5 :( The bug has been marked as "good-first-bug" so it's probably something easy to do. If you know some Firefox developer or somebody who wants to become one, this may be a good place to start :)
