I have a question. Hi Dawn, There are several things happening at once here, that may complicate your efforts. Falling on top during baking is a separate problem from not rising at all.
Yeast can be a tricky little critter.
So can the flours you choose to use. I'm going to assume here that all your trials were made with the same bread machine. Bread, even with a machine, is not always the same each time you bake. The first thought I have here is that your mix was kept separately from your other yeasts and flours. The machine bread mix may simply have had a fresher yeast package.