In a situation like this, always remember anemones are mobile and will go where they please. Assuming you have enough light it will settle in wherever it feels happy. It is possible depending on the light you have it could be too bright and he will only peak out for more once he's adjusted to the tank (sometimes can take a few months believe it or not)
Give it time and patience I'd say, and just keep an eye out that its inflated well, has a tight mouth unless expelling waste and keeps looking healthy