Player not moving or sprinting while jumping

Hello, my player isnt able to run and jump at the same time. I would like it to move while jumping at the same time. It just stops moving forward, jumps, and then starts moving again. How can i fix that?

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class PlayerMovement : MonoBehaviour
 {
     //VARIABLES
    [SerializeField] private float moveSpeed;
    [SerializeField] private float walkSpeed;
    [SerializeField] private float runSpeed;
 
    private Vector3 moveDirection;
    private Vector3 velocity;
 
    [SerializeField] private bool isGrounded;
    [SerializeField] private float groundCheckDistance;
    [SerializeField] private LayerMask groundMask;
    [SerializeField] private float gravity;
 
    [SerializeField] private float jumpHeight;
 
    //REFERENCIES
    private CharacterController controller;
    private Animator anim;
    
    private void Start ()
    {
        controller = GetComponent<CharacterController>();
        anim = GetComponentInChildren<Animator>();
    }
 
    private void Update ()
    {
        Move();
    }
 
     //GRAVITACE
    private void Move()
    {
        isGrounded = Physics.CheckSphere(transform.position, groundCheckDistance, groundMask);
 
        if(isGrounded && velocity.y < 0)
        {
            velocity.y = -2f;
        }
        
        float moveZ = Input.GetAxis("Vertical");
 
        moveDirection = new Vector3(0, 0, moveZ);
        moveDirection = transform.TransformDirection(moveDirection);
 
 
         //POHYB
         if(isGrounded)
         {
            if (moveDirection != Vector3.zero && !Input.GetKey(KeyCode.LeftShift))
             {
                 Walk();
             }
 
             else if(moveDirection != Vector3.zero && Input.GetKey(KeyCode.LeftShift))
             {
                 Run();
             }
 
             else if(moveDirection == Vector3.zero)
             {
                 Idle();
             }
 
             if (Input.GetKey(KeyCode.A))
             {
                  transform.Rotate(0, -1, 0);
             }
                         
                     
             if (Input.GetKey(KeyCode.D))
             {
                 transform.Rotate(0, 1, 0);
             }
 
             moveDirection *= moveSpeed;
 
             if(Input.GetKey(KeyCode.Space))
             {
                 Jump();
             }
     
         }
 
        controller.Move(moveDirection * Time.deltaTime);
 
        velocity.y += gravity * Time.deltaTime;
        controller.Move(velocity * Time.deltaTime);
    }
 
    private void Idle()
    {
        anim.SetFloat("Speed", 0, 0.1f, Time.deltaTime);
    }
 
    private void Walk()
    {
        moveSpeed = walkSpeed;
        anim.SetFloat("Speed", 0.5f, 0.1f, Time.deltaTime);
    }
 
    private void Run()
    {
        moveSpeed = runSpeed;
        anim.SetFloat("Speed", 1.5f, 0.1f, Time.deltaTime);
    }
 
     private void Jump()
    {
        velocity.y = Mathf.Sqrt(jumpHeight * -2 * gravity);
        anim.SetFloat("Speed", 1);
    }
 
 
    
 }
 
 

,Hello, my player cannot move forward or anywhere else when jumping. It just stops moving, jumps, and then starts moving again. I would like to be able to move also when the player is jumping at the same time. How can i fix that?

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