What is #shadow-root and why isn't it rendering awesome classes on my font?

Why are shadow root styles not showing display in my classes .fa-xxx

?

The shadow-root thing is adding the classes I use to render, not the piles, just the ones I add!

I am using PHP to include navigation, footers, etc., but it fails. For example, it works great in my navigation. There it displays the font fine.

What is causing this and how can I control it?