Comment # 5 on bug 1017767 from Markus Greger

Temporary workaround to open dolphin at least in the parent directory of the
mount

Edit /usr/share/solid/actions/test-predicate-openinwindow.desktop
Replace
Exec=/kde-open5 "%f"
With
Exec=/bin/sleep 1; [ ! -z "%f" ] &&  kde-open5 "%f" || kde-open5
"/run/media/$USER"