I got stuck, then I cheated

I got stuck, then I cheated - student project

This is the pattern based on a hexagon.

I could not make a clipping mask to make a pattern without white space.

I opened it in Illustrator, that was easy, but not the point of the exercise. Helen, where did I go wrong on the clipping mask? It wouldn't work with shape, path, or pixels. My only thought is it just has to be a square so the fit issue never comes up. Any hints?

Edit (later): I got more info from Pop Art Style Star Pattern, another class of yours that uses a pattern that makes a hexagon. It's not exactly the same, but it has similar fit issues. It's another beautiful pattern. Thanks so much for the great classes.