Character Controller Falling Through Floor

From the unity docs.
Character controller falling through floor. The character controller is mainly used for third person or first person player control that does not make use of rigidbody physics. I know that i need to detect the colli. I want to make a bouncing ball effect. In the details section for your player character mesh see if you have the box simulate physics checked or not.
However my object falls through the floor. This did not happen in the original opsive store version from sept 9th. When i use the character manager to build a character using a model from mixamo including but not limited to characters created in fuse the character immediately falls through the floor when i press play. While i cannot explain to you why exactly i do know that when fiddling around with physics stuff in the templates i would be able to play a level fine and then upon changing the value of that checkbox for either the floor or character mesh i was falling through the floor.
I attached a camera to my controller and i can see that it falls past the ground and continues to fall into infinity. Please do not put a rigidbody on a charactercontroller. I m using the official unity tutorial. It keeps falling through the floor.
On the object i added a rigidbody and it already has a box collider. Character controllers are not meant to be used with a rigidbody. I 39 ve gotten everything to work except my character controller.