Jumping makes the player jump 2 times,

I made a small script to make the player jump, so I can jump. I used a spherecast for the groundcheck, but the spherecast either doesn't let me jump at all (if the ray is too short), or makes me jump twice int two following frames. I made a variable that makes you unable to jump for some time after jumping, thinking that it would let me jump again when I was in the air already, but it still jumped twice, although I was clearly not touching the ground.

Code:

     float jump;
     
     int jumpCounter = 0;
     
     int noJump = 0;
     
     Rigidbody playerRb;
     
     RaycastHit groundRayInfo;
     
     public int noJumpFrames = 1;
     
     public float sphereRadius = 0.4f;
     
     public int jumpCount = 1;
     
     public float ray = 0.11f;
     
     public float jumpForce = 150;
     
     void Start()
         {
             playerRb = GetComponent<Rigidbody>();
             Time.fixedDeltaTime = 0.016666666666f;
             jumpCounter = 0;
         }
     
     void FixedUpdate()
         {
             jump = Input.GetAxis("Jump");
             Debug.Log("noJump " + noJump.ToString());
             Debug.Log("jumpCounter " + jumpCounter.ToString());
             Mathf.Clamp(jumpCounter, 0f, jumpCount);
             if (jumpCounter == jumpCount | noJump != 0)
             {
                 jump = 0;
                 Debug.Log("condition " + (jumpCounter >= jumpCount | noJump != 0).ToString());
             }
             if (jump == 1) 
             {
                 jumpCounter++;
                 noJump += noJumpFrames;
             } else 
             {
                 if (noJump > 0)
                 {
                     noJump--;
                 }
             }
             Debug.Log("jump " + jump.ToString());
             playerRb.AddForce(new Vector3(0f, Vector3.up * jump * jumpForce, 0f));
             if (Physics.SphereCast(transform.position, sphereRadius, Vector3.down, out groundRayInfo, ray))
             {
                 jumpCounter = 0;
             }
             Debug.DrawRay(transform.position, Vector3.down * +(ray + sphereRadius), Color.red); // Visual for me to adjust the ray length
         }
 

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