I found that using masks from PI, it works great if you save the selection rather than the mask itself. On the one below, I opened PI, dragged one of the masks to a blank image. That puts just the selection on the blank image. Then saved the selection as a .png.
In AD, I clipped the image inside of the selection. This is the result.. worked perfectly. It looks like there are many ways to reach the same goal - it depends on what we use as a mask. I rather like the selection method. Going to play with this a bit more.