Unity3D - Gravity Not Applying When Activating my Movement Script

Hi ! :) Sooo I kinda have a problem in Unity3d :

I use the following script to make my character move, my character only has a RigidBody, Capsule Collider and this Script (CharacterControllerCode.cs) attached. When i leave the script unchecked, the gravity applies as it should to the character but when I activate the script, the grvity does not apply anymore and the Character stays at the Y position assigned in the editor (Transform Component).

Does anyone have the smallest clue why this is happening ?

(i'm very new to c# and unity so i checked out this video to make the code https://www.youtube.com/watch?v=WIl6ysorTE0&list=PLYQCqA5CcgADEN4gGw7qdsqcN9ERUrHbM∈dex=19)

I'm using the New Input System Package btw

Script below ↓

    using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.InputSystem;

public class PlayerControllerCode : MonoBehaviour
{
   private PlayerControlInputs playerControlsAsset;
   private InputAction moveAction;

   private Rigidbody rigBod;
   
   [SerializeField]
   private float movementForce = 1f;

   
   [SerializeField]
   private float maxSpeed = 5f;

   [SerializeField]
   private float jumpForce = 5f;

   [SerializeField]
   private float dashForce = 5f;

   private Vector3 forceDirection = Vector3.zero;

   [SerializeField]
   private Camera playerCamera;
private void Awake() 
{
    rigBod = this.GetComponent<Rigidbody>();
    playerControlsAsset = new PlayerControlInputs();
}

private void OnEnable() 
{
    playerControlsAsset.PlayerActions.Jump.started += DoJump;
    playerControlsAsset.PlayerActions.Dash.started += DoDash;
    moveAction = playerControlsAsset.PlayerActions.Move;
    playerControlsAsset.PlayerActions.Enable(); 
}
   
private void OnDisable()
{
    playerControlsAsset.PlayerActions.Jump.started -= DoJump;
    playerControlsAsset.PlayerActions.Dash.started -= DoDash;
    playerControlsAsset.PlayerActions.Disable();  
}

    
    private void FixedUpdate() {

    LookAt();
    IsGrounded();
    forceDirection += moveAction.ReadValue<Vector2>().x * GetCameraRight(playerCamera) * movementForce;
    forceDirection += moveAction.ReadValue<Vector2>().y * GetCameraForward(playerCamera) * movementForce;

    rigBod.AddForce(forceDirection, ForceMode.Impulse);
    forceDirection = Vector3.zero;

    Vector3 horizontalVelocity = rigBod.velocity;
    horizontalVelocity.y = 0;

    if(rigBod.velocity.y < 0f)
    {
        rigBod.velocity += Vector3.down * Physics.gravity.y * Time.fixedDeltaTime;
    }

    if(horizontalVelocity.sqrMagnitude > maxSpeed * maxSpeed)
    {
        rigBod.velocity = horizontalVelocity.normalized * maxSpeed + Vector3.up * rigBod.velocity.y;
    }

    


}

private void LookAt()
{
    Vector3 direction = rigBod.velocity;
    direction.y = 0f;

    if(moveAction.ReadValue<Vector2>().sqrMagnitude > 0.1f && direction.sqrMagnitude > 0.1f)
    {
        this.rigBod.rotation = Quaternion.LookRotation(direction, Vector3.up);

    }
    else 
    {
        rigBod.angularVelocity = Vector3.zero;

    }

}

private Vector3 GetCameraRight(Camera playerCamera)
{
    Vector3 right = playerCamera.transform.right;
        right.y = 0;
        return right.normalized;
}

private Vector3 GetCameraForward(Camera playerCamera)
{
        Vector3 forward = playerCamera.transform.forward;
        forward.y = 0;
        return forward.normalized;
}

    private void DoJump(InputAction.CallbackContext obj)
{
    if(IsGrounded())
    {
        forceDirection += Vector3.up * jumpForce;

    }
}



private void DoDash(InputAction.CallbackContext obj)
{
        forceDirection += moveAction.ReadValue<Vector2>().y * GetCameraForward(playerCamera) * dashForce;
}


private bool IsGrounded()
{
    Ray ray = new Ray(this.transform.position + Vector3.up * 0.05f, Vector3.down);
    if(Physics.Raycast(ray, out RaycastHit hit, 0.1f))
     {return true;}
    else
     {return false;}

}
}

My Hierarchy

My Character's Components