Hilarious Gravity defect i don't know how to fix

So after making a basic-ish enemy script and animations I tested it out and if I where to ever go higher in elevation they would just fly to me. So to simulate gravity i attached a character controller and character motor and when I hit play they all disappeared one by one,after a minute I discovered they had all fallen through the world if ever a slight incline in terrain were to ever come across them. Is there a way to stop this?, or a better solution.

i’ve solved by adding one more collider just at the bottom of the enemy, or you can try adding a rigidbody, freezing the z and x (i think but not sure) rotations