Problems with character based on btPairCachingGhostObject and btKinematicCharacterController

[native-engine]

I created a character based on btPairCachingGhostObject and btKinematicCharacterController and two questions arose at once: the character constantly moves jerkily and he moves noticeably faster when he rotates the mouse. How can I get rid of these annoying drawbacks? And I want to ask - is it possible for btPairCachingGhostObject, as well as for btRigidBody, to assign the class btMotionState or something like that, so that the camera does not update when there is no movement or rotation of the character?

[native-engine]

The next line is: walkSpeed = walkVelocity * dt; replaced the line walkSpeed = walkVelocity / GameData.threadData.gameTimer.trueFPS; and moving the character, including rotations, became stable. But the question about using the btMotionState class or its analog for the btPairCachingGhostObject / btKinematicCharacterController object still stands.