I'm leaving this thread here for others who search the forums for answers. You're not going crazy, you won't find discounted (often times) $5 Tuesday tickets on Fandango or Atom tickets anymore for Cinemark theaters. In order to get the discounted price you must use Cinemark's app or buy them at your local movie theater. Cinemark charges their own "convenience fee" on their app/website.
Atom tickets got rid of Regal theaters and instead added Cinemark theaters in their place.