Custom cursor not showing up in full screen

Hi all. I've got a strange issue: I've got a png with transparency that I am using for a cursor during part of my game. the "Texture Type" is set to "Cursor" and it works great if you're 1) playing in the editor or 2) playing in a window.

As soon as you start the game full screen (doesn't matter the resolution), the cursor never changes from the default Windows cursor.

Here's the code I'm using to set the cursor. This script is attached to the main camera in every scene. If I want the cursor to be custom, I set a texture, and the script does the rest. Otherwise, I leave the texture field blank, and uses the windows default. I've also tried setting this to the Awake function, with no change.

 using UnityEngine;
 using System.Collections;
 
 public class SetCursor : MonoBehaviour {
 
     public Texture2D cursor;
     private Vector2 hotspot;
 
     void Start () {
         if (cursor != null)
         {
             hotspot = new Vector2(cursor.width / 2, cursor.height / 2);
         }
         else {
             hotspot = new Vector2(0, 0);
         }
         Cursor.SetCursor(cursor, hotspot, CursorMode.Auto);
 
     }
 
 }

Alternatively, if there's a better way I could be doing this, I'd be happy to learn!

Thank you in advance!