Fontella Icons Not Showing right Title on Site

I am having the same problem as this person here:

https://kriesi.at/support/topic/imported-fontella-icons-but-not-showing-correctly-on-site/

I’ve followed everything on the forum, and followed all the links to right threads. I imported a new fonttella icon (Thumbtack) and when a user hovers over the title, it says” Icon_name”.

This is what we added to our Functions.php

// Register new icon as a theme icon
function avia_add_custom_icon($icons) {
	$icons['icon_name']	 = array( 'font' =>'customfont', 'icon' => 'ue822');
	return $icons;
}
add_filter('avf_default_icons','avia_add_custom_icon', 10, 1);

// Add new icon as an option for social icons
function avia_add_custom_social_icon($icons) {
	$icons['Thumbtack'] = 'icon_name';
	return $icons;
}
add_filter('avf_social_icons_options','avia_add_custom_social_icon', 10, 1);

For whatever reason, the “icon_name” keeps on showing up as the title. On the thread that I linked to above, Jose solved the issue but he didn’t say what code he changed or what he did.