Yes tried it all.
I’m no Photoshop guru, but it seems to me that the alpha channel is there, but I need to open up the document, go into channels choose my lowest channel that’s being called Alpha 1. Then go into load channel as selection and hit delete to get where I want!
With the PNG I just drag the file into an open photoshop document and I’m in business.
I should maybe be asking these questions in the photoshop forum?