Character shaking on moving platform (elevator)

I have the exact same problem, a shame there are no answers yet. Actually that's true for most threads where it seems that that must have been solved before.

I ended up trying to get the difference between my elevator position and last frame position and add that to whatever enters the trigger- but it always returns 0. That may be an hierarchical problem. Currently I don't get why it would not calculate the difference right, but I'll look at it again tomorrow.

[TOMORROW EDIT]

ok, ive got half of it - I used an empty with Character Controller and had a Child with a capusle Collider and Rigidbody so i could bump into physic objects like boxes and stuff, that was part of the problem. Now I moved the Collider and Rigidbody to the empty where the Character Controller is and in the Elevator Sticky Zone I used the difference position as a kind of velocity for everything that is on the elevator:

 void Update(){
     Vector3 dif = transform.position - previousPos;
 
     foreach (GameObject o in objs) {
         if(o.GetComponent<CharacterController>() != null) {
             o.GetComponent<CharacterController>().Move(dif);
         } else {
             o.transform.position += dif;
         }
     }
 
     previousPos = new Vector3(transform.position.x, transform.position.y, transform.position.z);
 }

objs is a list of gameObjects that gets filled and emptied on TriggerEnter and Exit @gbagiryan

This works for left, right and up movement, the down movement is somewhat jerky again, I suspect bc of gravity or the antificial gravity in the character controller - with 0 gravity it works fine. 0 gravity messes up how you walk over slopes though, so you need something that zeroes it on the elevator.