JSFiddle - React, Tailwind, and code Playground

HTML

<p class="edit" contenteditable="true">*Double-Click a section to 'selectAll'.</p><br>
<p class="edit" contenteditable="true">This content is static. Firefox edits fine.</p><br>

<div id="live"></div>

CSS

p { background-color:  #eff1f1; width: 300px; padding: 10px; }

JavaScript

$(document).ready(function(){
$('.edit').live('dblclick', function () {
    document.execCommand('selectAll',false,null);
});

$('#live').append('<p class="edit" contenteditable="true">This content is generated. Firefox will not allow keyboard input when "ALL" is selected.</p>');
});