Target ML-Agents falling random down HELP PLS :(

Im trying to perform a simple AI using mlagents last version, everithing is fine with version python pytorch etc but i have an issue, after attaching the script and writing the basic movement istructions my target, witch should be static fall down the plane. and my agent try to catch with a self rotation.

This is my code for the Agent script

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using Unity.MLAgents;
 using Unity.MLAgents.Sensors;
 using Unity.MLAgents.Actuators;
 
 public class CorpFollowThief : Agent
 {
      [SerializeField ]private Transform thiefPosition;
 
     public override void OnEpisodeBegin()
     {
         transform.position = new Vector3(0, 1, 2);
     }
     public override void CollectObservations(VectorSensor sensor)
     {
         sensor.AddObservation(transform.localPosition); //3 x y z
         sensor.AddObservation(thiefPosition.localPosition); //3 x y z
        
     }
     public override void OnActionReceived(ActionBuffers actions)
     {
         float movementSpeed = 1f;
         float moveX = actions.ContinuousActions[0];
         float moveZ = actions.ContinuousActions[1];
 
         transform.position += movementSpeed * Time.deltaTime * new Vector3(moveX, 0, moveZ);
     }
 
     public override void Heuristic(in ActionBuffers actionsOut)
     {
         ActionSegment<float> continuousAction = actionsOut.ContinuousActions;
         continuousAction[0] = Input.GetAxisRaw("Horizontal");
         continuousAction[1] = Input.GetAxisRaw("Vertical");
     }
     private void OnTriggerEnter(Collider other)
     {
         if(other.TryGetComponent<Thief>(out Thief thief))
         {
             SetReward(1f);
             EndEpisode();
         }
         if (other.TryGetComponent<Wall>(out Wall wall))
         {
             SetReward(-1f);
             EndEpisode();
         }
 
     }
 
 
 }