The Variable {{ siteUrl }} Produces Two /es/es/ On Multisite
I figured out what was wrong, though I'm confused on why some of it was working fine... Maybe if it broke more fully I would have found it easier, haha. Mats was right, it was the Base URL in the Sites area of the admin control panel. I had entered @web/es thinking that I want it to be the root of the primary site, but that wasn't correct, I needed to just put @web/ because I already told it that it lived at /es through the index.php of that site folder.