Character jumps to high on start moving

So I have got a player which needs to move and be able to jump. The player moves just fine but when I jump while pressing any movement keys it jumps about 4-5 times higher than usual.

Code:
void FixedUpdate()
{
Movement();
}

    private void Movement()
    {
        if (airControl || grounded)
        {
            float h = Input.GetAxis("Horizontal") * moveSpeed / 2000;
            float v = Input.GetAxis("Vertical") * moveSpeed / 2000;

            rb.MovePosition(transform.position + (transform.forward * v) + (transform.right * h));

            if (Input.GetButton("Run"))
            {
                moveSpeed = runSpeed;
            }
            else
            {
                moveSpeed = walkSpeed;
            }

            if (Input.GetButtonDown("Jump") && grounded)
            {
                Jump();
            }
        }
        
            grounded = false;
    }

Thanks in advance.

I think it’s this line:
float h = Input.GetAxis(“Horizontal”) * moveSpeed / 2000;
You are setting the horizontal movement to your moveSpeed, so the faster you are moving the higher you will jump.
You should also post your Jump function to see if it’s an issue in there.

I changed my code a bit and now it looks like this:

float h = 0;
        float v = 0;

        if (Input.GetKey(kc.keys.forward))
            v = 1;
        else if (Input.GetKey(kc.keys.back))
            v = -1;

        if (Input.GetKey(kc.keys.right))
            h = 1;
        else if (Input.GetKey(kc.keys.left))
            h = -1;

        Vector3 movement = new Vector3(h, 0, v).normalized;

        h = movement.x;
        v = movement.z;

        Vector3 desiredForward = Vector3.Normalize(new Vector3(cam.transform.forward.x, 0, cam.transform.forward.z));
        Vector3 desiredRight = Vector3.Normalize(new Vector3(cam.transform.right.x, 0, cam.transform.right.z));

        rb.AddForce(desiredForward * v * speed);
        rb.AddForce(desiredRight * h * speed);

        if (Input.GetKeyDown(kc.keys.jump) && grounded)
        {
            rb.AddForce(Vector3.up * jumpForce, ForceMode.Impulse);
        }