We are trying to access a publicly accessible ArcGIS Online application from our Enterprise portal (via a "Site") where it is part of a gallery card. We can access the application fine without the extra qualifiers site puts into the URL, (namely, sites/#/publicworks.) The site is shared as public on AOL, and the Gallery entry on our site is shared publicly as well. When the gallery card's View Application is clicked, it gives a sad emoji and the error: "Item does not exist or is inaccessible." This happens for a couple of different AOL apps being accessed from our enterprise "Sites". Can portal communicate with ArcOnline or is some sort of collaboration/federation necessary?
Any help appreciated.