Looks a lot more like Microsorm pteropus 'Windeløv' ( yep, I can do the "ø"-letter😉 ), to me.
It's also a very easy plant to grow, but not a stem-plant like Hygrophila difformis.
Microsorum does not really like being planted in the substrate/gravel - but likes a spot on a piece of wood or a rock very much, since it's an epiphyte in nature.