My anemone went down under a rock about a week ago, split, and neither one has come back out yet. Both still have good color and bubble up nicely. What's the longest one has stayed hidden?
What lighting do you have?
Tank history and params would help.
Hiding is not a good thing, I'm wondering if it was under weaker light when you purchased it, if so screen netting is good for acclimation.
Splitting is common when intro'd to new tanks/params, they tend to stress.
You called it. I originally had it in a 55gal with t5 and now it's a 210gal with reef breeder photons. For the first 3 weeks it looked pretty content, then it just moved and split. They haven't moved but are still bubbling up quite a bit and the clown is going between the 2.