Downloaded RDF files gets opened in epiphany when opening them from the download popover, then downloaded again as Epiphany can't show them

Steps

Download this RDF sample file
open the downloads popover
click the file in the list

Current behaviour

The file is opened in epiphany (as a new opened tab indicates), but epiphany can't show it so it downloads it again.

Expected behaviour

Epiphany doesn't do this and just opens an external program instead.

Interestingly when I run xdg-mime query filetype foobar.rdf, it prints application/rdf+xml, but with xdg-mime query default application/rdf+xml it doesn't show any app (not even epiphany). So I assume that either Epiphany opens the file in itself when there's no app to open it, or that it's related to epiphany having text/xml as mime type handler in the desktop file.

Reproducable with both stable epiphany from flathub and the gnome-nightly one.