compound path was separate by using path finder

Hi! I am trying to make an animated optical illustion in illustrator. I first select the target of a layer, but as i'm trying to use the path finder tool "minus front," it keeps separating my compound path into a group of many paths. 

I am a beginner in illustrator so there's still things i'm unfamiliar with, if anyone could help me out from this i will be beyond greatful. Thank you!

This is the tutorial i am following: https://www.youtube.com/watch?v=mwTcZPKVyj0&t=696s