"Dash-Move" only work some times.

I have a problem with my dash move. It just work some times. Mby 1 out of 3 times. I also found out that it works more often if i press the jump key (SPACE) at the same time. Does it colide with the jump code? Any ideas how to fix it?

I marked the "dash code" with //Dash. I hope u can read the code im new in coding :D

Here is the code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class PlayerControl : MonoBehaviour
 {
     private Rigidbody2D rb;
     public float speed;
     public float jumpForce;
     private float moveInput;
 
     private bool isGrounded;
     public Transform feetPos;
     public float checkRadius;
     public LayerMask whatIsGround;
 
     private float jumpTimeCounter;
     public float jumpTime;
     private bool isJumping;
     private bool facingRight = true;
 
     //Dash
     public float dashSpeed = 30f;
     public float startDashTime = 0.1f;
     private float dashTime;
     private int direction;
 
 
     private void Start()
     {
         rb = GetComponent<Rigidbody2D>();
 
         //Dash
         dashTime = startDashTime;
     }
 
     private void FixedUpdate()
     {
         moveInput = Input.GetAxisRaw("Horizontal");
         rb.velocity = new Vector2(moveInput * speed, rb.velocity.y);
 
         if (facingRight == false && moveInput > 0)
         {
             Flip();
         } else if(facingRight == true && moveInput < 0)
         {
             Flip();
         }
 
         void Flip()
         {
             facingRight = !facingRight;
 
             transform.Rotate(0f, 180f, 0f);
         }
 
         //Dash
         if (direction == 0)
         {
             if (Input.GetKeyDown(KeyCode.LeftShift))
             {
                 if(moveInput < 0)
                 {
                     direction = 1;
                 } else if (moveInput > 0)
                 {
                     direction = 2;
                 }
             }
         } else
         {
             if(dashTime <= 0)
             {
                 direction = 0;
                 dashTime = startDashTime;
                 rb.velocity = Vector2.zero;
             } else
             {
                 dashTime -= Time.deltaTime;
 
                 if(direction == 1)
                 {
                     rb.velocity = Vector2.left * dashSpeed;
                 } else if (direction == 2)
                 {
                     rb.velocity = Vector2.right * dashSpeed;
                 }
             }
         }
         //Dash End
     }
 
     
 
     private void Update()
     {
         isGrounded = Physics2D.OverlapCircle(feetPos.position, checkRadius, whatIsGround);
 
         if(isGrounded == true && Input.GetKeyDown(KeyCode.Space))
         {
             isJumping = true;
             jumpTimeCounter = jumpTime;
             rb.velocity = Vector2.up * jumpForce;
         }
 
         if (Input.GetKey(KeyCode.Space) && isJumping == true)
         {
             if(jumpTimeCounter > 0)
             {
                 rb.velocity = Vector2.up * jumpForce;
                 jumpTimeCounter -= Time.deltaTime;
             } else {
                 isJumping = false;
             }
 
         }
 
         if (Input.GetKeyUp(KeyCode.Space))
         {
             isJumping = false;
         }
 
     }
 
 }
 

Thank you.