Every single one of mine will put their foot on 2 seperate rocks or structures and pull themselves apart... I would keep an eye on it it might not be splitting now but if its been in tank a while in same spot and just got a wild hair and started wondering it may be getting ready to split but its searching for the best place to do so, make sure your power heads are covered because it may take it a day or so to find the best place to split and could search entire tank pretty quickly. Also Mine always split at night when lights are off might be a coincidence but it may not...
****Edit: Just saw previous post... Since its new to tank its more than likely just searching for a spot it likes, their foot can look funny at times, but it splits at the mouth not at the foot or its column if it is splitting at the foot the foot is damaged and thats a long recovery. Key right now it is best to let him settle down, don't feed it until he does settle down and is happy for a day or so and when you do feed it small portions is key , a good rule of thumb is if its pooping you fed it to much, also from my experience the more I mess with mine or change conditions of tank the Anemone is the first to let me know he is not happy stability is key with nems.