Some class mounts not counting toward mount total

Been working on getting alts up to speed with Legion class mounts and have noticed two out of my currently finished six character have not counted. Classes that have been completed and counted toward the total are my hunter, death knight, demon hunter, and paladin.

The two classes whose mounts have not been counted are my warrior and mage (so far).

How do I get these two class’ mounts to count toward the mount total? I’ve tried logging in/out, mounting in every spec (since for some reason they don’t just have separate mounts) and have yet to find out a way to make this happen when I have verified through others that they should count.

Please check my answer here Achievement not updating mount count - #15 by Neavil-frostmourne.