I can't propagate okinawa and longevity spinach

I'm having a rough time trying to propagate my okinawa and longevity spinach I've tried them in water, or soil, sand, with small cuttings big cuttings, more leaves, less leaves...

They do grow fast, but I thought they were supposed to be easy to propagate, is there any technique to make the cuttings grow roots?

Gynura bicolor
Gynura procumbens

Welcome to permies Valquir Souza.  I was hoping that someone with experience with this plant would answer but a few days have passed without a response so I will try to help you.
Generally plants of this type will only root with a growing tip and at least one leaf node with the leaf removed below the surface of the water or soil.
Instructions on line say:
Longevity Spinach is quite easy to grow and propagates readily from cuttings placed in water. You can also take cuttings with two or three leaves attached, dip the cut end in rooting hormone powder, and plant them immediately in moist soil. Nov 20, 2019  Longevity Spinach is quite easy to grow | Cape Gazettehttps://www.capegazette.com › article › longevity-
Some may root best by laying the branch down on the soil and covering the leaf node then cut it off after it has formed roots.