Getting the real filename from Gtk.FileChooserNative

I’m getting a file name using Gtk.FileChooserNative file picker. In snap instead of returning an actual file path dialog.get_filename() returns a path in /run location, e.g.

/run/user/1000/doc/2ece1911/amixer

Is there a way to get real file name? My code looks like follows:

        dialog = Gtk.FileChooserNative(
            title="Select an icon",
            action=Gtk.FileChooserAction.OPEN,
        )
       # omitted
       filename = dialog.get_filename()

I’ve tried get_preview_filename, get_current_name with no luck.