Animation stopping object rendering on Android device

If I create a blank scene, add a cube and attach an Animation Controller to it, then create a blank Animation and add that to the Animation Controller and then run the game in the editor - all is good.

If I then edit the Animation to spin the cube in the editor and run - all is still good.

My problem is, if I then push this to my attached Android device, the cube is not rendered - even though it is rendered in the editor.

The issue has something to do with the animation clip itself, as the cube will render on the Android device if an animation clip is empty.

If there is somewhere practical to upload the sample scene file, let me know and I'll do that.