I changed my normal wordpress installation to multi site so that I could have support for multisite plugins here.
Previously I had a single wordpress installation. It also ran on a different domain. I changed the domain before I changed to multi-site. When I changed the domain, I used the wp-config.php overrides to change it (not within the wp-admin settings). Now out of no where when I upgraded to a multi site and ran the install, it is directing me to the old domain.
P.S. I did make a backup of my installation if I need to do anything before the multi-site upgrade.