Firefox not properly applying Pseudo Before and After classes in Firefox Windows only

In this Codepen : https://codepen.io/trevcis/pen/rgRePm

As you rollover a picture, a green expand box is shown that has a plus sign drawn with before/after pseudo classes on the 'close-toggle' div.

A seemingly similar problem at: https://stackoverflow.com/questions/21220360/firefox-not-displaying-properly-before-and-after-pseudo-elementshttps://stackoverflow.com/questions/21220360/firefox-not-displaying-properly-before-and-after-pseudo-elements

Seemed to fix the problem by applying inline-block/postiion:relative to it's parent, but it doesn't seems work.

It's 'weird' that Firefox on the Mac works just fine so would it be more of a bug in FireFox Windows? In fact it works on ALL other browsers that I tested it on.

This is code I inherited and was contemplating a rewrite but seems there's some approach that would fix it.

I tried applying the fix (set position/display on parent) that is in the somewhat related issue post:

.close-toggle, .PeopleBlock{
    position:relative;
    display:inline-block;
}

but it is the same result