Hydrocotyle tripartita 'Japan' not staying in substrate

[tnnlynch]

Picked up two healthy pots from the coop the other month and planted them in a newly re-scaped 10g.  Substrate is plain gravel with root tabs.  Easy green once a week. No CO2.  Finnex light. 

I keep finding floating stalks of the plant with the lowest portion rather mushy.  No fish but there are mystery snails.  Is this a substrate issue or are my snails pulling the plants out while cruising the tank?   I have seen the larger snails strip the roots off of my frogbit  but I have never actually seen them on these plants.

[JettsPapa]

I doubt the snails are the problem.  I also struggle with keeping it in the substrate, and I have sand in my tanks.

[tnnlynch]

Bummer. I was hoping for a quick fix.  🙁