hi...Why the character stays on top of the terrain?

Hi @Itachi999, the default PhysX characters do not automatically apply gravity. Related forum post: Gravity with PhysX character controller
PhysX documentation (Kinematic controller) https://docs.nvidia.com/gameworks/content/gameworkslibrary/physx/guide/Manual/CharacterControllers.html

Normally what I do is apply gravity in ScriptCanvas, Lua or C++ when I update my player’s movement . We are currently considering some options to automatically apply gravity for common scenarios like the legacy character component did.