Hi matthew,
Thanks for contacting us and choosing our product!
1. About you problem. Due to conflict with template. Please go to CSS3 Mega Menu module -> tab advanced -> config custom css
add css
#jux_megamenucss3 .megamenu .js-megamenu.container{
margin: 0px auto;
background-color:#297c7f;
}
Your problem may not work sticky menu. because you are using a different software to load the JS library and it has blocked all JS files loaded from the module. Please check again. or you can send me an account site via message private. Thanks
note: Maybe you're using this software
extensions.joomla.org/extension/jquery-easy