mousePosition not working for Mac build

This rotation and movement script I have on the player works perfectly fine in the editor and Windows builds, but for some reason on the Mac the player will rotate back and forth instead of focus in on one spot. Here's the general gist of my code: Sorry it's pretty messy, I was trying to cut out only the seemingly important parts.

     void Update () {
 
 
 
         ray = mainCam.GetComponent<Camera>().ScreenPointToRay (Input.mousePosition);
 
         if (plane.Raycast(ray, out distance)) {
             hitPoint = ray.GetPoint (distance);
         }
 
 targetAngle = Mathf.Atan2 (hitPoint.z - transform.position.z, hitPoint.x - transform.position.x);
         
         float val = ((-Mathf.Rad2Deg * targetAngle + 90) - (transform.eulerAngles.y));
 
 
         if (Mathf.Abs (val % 360) > 5) {
             //Debug.Log(Mathf.Abs (val % 360));
 
             if((Mathf.Abs ((val % 360)) > 180)){
                 if (360 - Mathf.Abs ((val % 360)) > 5) {
                     rb.angularVelocity = new Vector3 (0, ((Mathf.MoveTowardsAngle (transform.eulerAngles.y, -Mathf.Rad2Deg * targetAngle + 90, 1) % 360) - (transform.eulerAngles.y % 360)) * rotSpeed, 0);
                 } else {
                     rb.angularVelocity = Vector3.zero;
                 }
             }else{
                 rb.angularVelocity = new Vector3 (0, ((Mathf.MoveTowardsAngle (transform.eulerAngles.y, -Mathf.Rad2Deg * targetAngle + 90, 1) % 360) - (transform.eulerAngles.y % 360))* rotSpeed, 0);
             }
 
 
             if (val % 360 > 180 || val % 360 < 0) {
                 //rb.angularVelocity = new Vector3 (0, -rotSpeed, 0);
             } else {
                 //rb.angularVelocity = new Vector3 (0, rotSpeed, 0);
             }
 
         } else {
             rb.angularVelocity = Vector3.zero;
         }