Hi and welcome!
The nem looks to be quite happy just laying there, doing it's things.
Nems gunna do what a nems gunna do sometimes (usually)
When I'm introducing sand dwellers, I cut the majority of the flow off temporarily, clear out a deep hole all the way down to the glass, introduce the foot down into the hole, then backfill sand around the foot about to where the color starts changing.
Ltas do love to move when things change. If it doesn't stick where you want it, it'll move around attempting to find a spot it prefers.
Is it can stay healthy looking as it does, I wouldn't be worried in the slightest.
It may never anchor down in the sand. I've got a Big ol Condi that lives that the Very peak of my rock work in high direct flow, and right under the lights.
Nems doin nem things.
