I returned to Adobe Express, "My Stuff" to redownload a file I had already removed the background from, and even though it let me choose .png file which typically equals transparency, the background was still slid white — even though the first time I used the AI function and downloaded immeditately, it gave me the layered PNG file with a true transparent background. This seems like a bug to not offer the same file originally created, but now saved under the tab "YourStuff."