Character Controller changes in Y

My character has an animation controller on it.
It works fine.
Then I added a Character Controller for collisions etc.
This also works fine BUT …

When the animation starts the character and controller change in Y and the anim plays as expected.
I take off the Character Controller and the character stays where it should in Y and the animation plays as it should as well.

Any suggestions as to why the Character Controller is rising in Y?

Yes such was and at me when I only started working with animation and CharacterController. Business that CharacterController in addition to Height parameter, have also a Skin Width parameter. It as though increases controler area. And the full height of your character shall add as: hCharacter = hController + 2*SkinWidth. Therefore knowing height of your character (in value of Unity), you can calculate mid point of the controler, as (0, hCharacter/2, 0). And also to learn controler height on a y axis that it didn’t displace at the beginning. (on the formula given by me).