rigid body can rotate but will not move

Hello Unity forums (: I am trying to build a vuforia AR game. I followed this guide: https://www.youtube.com/watch?v=khavGQ7Dy3c And succeeded in making it fully functional, with the character walking around(using .velocity) and rotating to face the direction it moves in(using .transform.eulerAngles). However, once I swapped out the character model for a different model(In my case, a beating heart), the replacement model could still move around but could no longer rotate. I tried changing the model scale (.transform.localScale) but that didnt work either. It seems that the rb.velocity still functions normally but not the rb.transform.localScale or rb.transform.eulerAngles methods. I remembered to attach a rigid body component to the new model and also to drag them into the appropriate inspector boxes. Please send help i am out of ideas. Here is my code, just in case yall wanna look at it. Note that there are some really lame questionable things I did in the code like converting a byte into a string then into an int then into a float. But for now I need to solve the most pressing issue which is the transform not working.

thank you so much for your help ((':

 using System.Collections;
  using System.Collections.Generic;
  using UnityEngine;
  using UnityEngine.UI;
  
  public class overseer : MonoBehaviour
  {
      public Text txt;
      public GameObject character;
      public GameObject SpawnPoint;
  
      public GameObject Plane;
  
      public Rigidbody rb;
      public Animation anim;
      byte[] BLEin = new byte[4]{0,0,0,0};
      int inInt;
      float inFloat;
      string inString;
      public textChanger00 textChanger00;
  
      float x = 0;
      float y = 0;
     // float z = 0;
  
      float angle;
  
      
      // Start is called before the first frame update
      void Start()
      {
          rb = character.GetComponent<Rigidbody>();
          anim = character.GetComponent<Animation>();
          textChanger00 = GameObject.FindObjectOfType<textChanger00>();
         // character.transform.position = new Vector3(0f,1f,-6f);
         // rb.transform.position = new Vector3(0f,0f,0f);
      }
      void FixedUpdate()
      {
          Vector3 movement = new Vector3 (x,-0.05f,y);
          rb.velocity = movement * 4f;
      }
  
      // Update is called once per frame
      
      void Update()
      {
          BLEin = textChanger00.getBytes();
          //inFloat = System.BitConverter.ToSingle(BLEin,0);
          //inInt = System.BitConverter.ToInt32(BLEin,0);
          //Debug.Log(System.BitConverter.getBytes(BLEin));
          //inInt = int.Parse(BLEin);
          //txt.text = System.Convert.ToBase64String(textChanger00.getBytes());
         // txt.text = Encoding.Default.GetString(textChanger00.getBytes());
        // txt.text = System.BitConverter.ToString(textChanger00.getBytes()); //works!
         // txt.text = System.BitConverter.ToString(BLEin); // this also works
  
          inString = System.BitConverter.ToString(BLEin);
          inInt = System.Int32.Parse(inString, System.Globalization.NumberStyles.HexNumber); // aw shit this works. its stupid but it works
          inFloat = inInt/10;
          //txt.text = inString;
  
          //Debug.Log(inInt);
  
          //TEST CODE START HERE
         // Vector3 scale = new Vector3 (inFloat,inFloat,inFloat);
         // rb.transform.localScale = scale;
          //TEST CODE END HERE
  
  
  
        //okay so this works. the in the byte array, when working from 0 to 5, only 0th index changes 
         
         switch (BLEin[0])
         {
             case 1:
              txt.text = "UP";
              y = 1;
              x = 0;
              
              angle = 0;
            //  anim.Play("walk");
             break;
  
             case 2:
              txt.text = "DOWN";
              y = -1;
              x = 0;
              
              angle = 180;
             // anim.Play("walk");
             break;
  
             case 3:
              txt.text = "LEFT";
              x = -1;
              y = 0;
              
              angle = -90;
            //  anim.Play("walk");
             break;
  
             case 4:
              txt.text = "RIGHT";
               x = 1;
              y = 0;
              
              angle = 90;
            //  anim.Play("walk");
             break;
  
             case 5:
              txt.text = "A";
             break;
  
             case 6:
              txt.text = "B";
              x = 0;
              y = 0;
              
  
             break;
  
  
             default:
              txt.text = " ";
              x = 0;
              y = 0;
              
            //  anim.Play("idle");
             // rb.velocity = Vector3.zero;
             // rb.Sleep();
             break;
         }
  
  
  
         Vector3 movement = new Vector3 (x,0,y); // no y component because not moving up and down
          
          rb.velocity = movement * 4f;
          rb.transform.eulerAngles = new Vector3(0,angle,0);
  
          if (rb.transform.position.y < Plane.transform.position.y - 2)
          {
              rb.transform.position = SpawnPoint.transform.position;
  
          }
          
  
  
  
      }
  
      
  }