I have GM for Mac, but the image_index variable works just fine for me. Are there any other pieces of code in the game that are interfering with this?
I have other codes, scripts, objects, and controllers present. They are working fine, it's until I activate the specific controller for what I'm trying to accomplish the draw_sprite index do I run into any sort of hindering problem.
If the controller had a sprite, it would show, maybe it's a problem with the sprite? It's worked fine in another previous test game.
Did you want to give it a try?