Parent class cannot find component

Hi All, beginner here. Please be gentle.

I am following a tutorial series on youtube and have hit a snag. The parent class (Character) seems unable to get the childs class' Rigidbody2D and fails to set it's velocity.

The rigidbody2d component is deinitely there and I can't seem to find any typos...so I'm a bit miffed.

The error being thrown is a null reference exception directed at Move(), where the velocity is set.

 Here is the parent class:
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public abstract class Character : MonoBehaviour 
 {
     [SerializeField]    
     private float speed2 = 5f;
 
     //animation code
     //private Animator animator;
 
     protected Vector2 direction;    
 
     private Rigidbody2D rb2d;
 
     // Start is called before the first frame update
     void Start()
     {
         rb2d = GetComponent<Rigidbody2D>();
 
     }
 
     protected virtual void Update()
     {

     }
 
     private void FixedUpdate()
     {
         Move();
     }
     
     public void Move()
     {
         //transform.Translate(direction * speed2 * Time.deltaTime); 
 
         rb2d.velocity = direction * speed2;     //null reference exception thrown here
     }
 }

Here is the player script:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Player2 : Character
 {
     void Start()
     {
         direction = Vector2.up;
     }
 
     protected override void Update()
     {
         GetInput();
         base.Update(); 
     }
 
     private void GetInput()
     {
         direction = Vector2.zero;   
 
         if (Input.GetKey(KeyCode.W))
         {
             direction += Vector2.up;
         }
         if (Input.GetKey(KeyCode.A))
         {
             direction += Vector2.left;
         }
         if (Input.GetKey(KeyCode.S))
         {
             direction += Vector2.down;
         }
         if (Input.GetKey(KeyCode.D))
         {
             direction += Vector2.right;
         }
     }
 }

To recap, the Character class cannot find the Rigidbody2D component of the Player2 class. This prevents setting of the Rigidbody2D velocity and therefore prevents player movement (and I cannot locate what the issue could possibly be).

Cheers