Since your question has nothing to do with video (although the presence of this library made me move it to this section), it is better to remove everything not related to video, ie. keep only the logic of your buttons, since these are what is problematic, to show to us.
Although I think I spotted the error in your code by reading it (but sometime, it is harder, and running the code can help).
Basically, there is an inefficiency with your code: whatever the conditions, you display the background. So, you can move all the calls to image(img) to the start of draw(), where it is called traditionally.
And it will probably solve your problem: because once you have drawn the first button, you hide it with the next call to image(img), actually!
Likewise, the multiple calls to the video between each button is redundant. Better move this to the end of draw().
Although I think I spotted the error in your code by reading it (but sometime, it is harder, and running the code can help).
Basically, there is an inefficiency with your code: whatever the conditions, you display the background. So, you can move all the calls to image(img) to the start of draw(), where it is called traditionally.
And it will probably solve your problem: because once you have drawn the first button, you hide it with the next call to image(img), actually!
Likewise, the multiple calls to the video between each button is redundant. Better move this to the end of draw().