I wrote about keyboard, not joystick, just i think disabled joystick still detects by game as pressed. I think it's unity bug with joystick detection. Now i remember something like that with other game based onto same unity template.
I don't know about the joystick detection till now as I have just started, I think you should only play on keyboard rather than the disabled joystick, I hope it will solve the problem!
I have launched my first game and so I do not know about these topics!
Sorry if my comment sounds too aggressive. My English not so perfect... I don't critique your game, just inform you about that bug possible at some configurations.
It's cool for 11yo... Even based onto unity example. I myself could have done even less even when I was 13yo...