is this normal bubble tip anemone behavior?

[Mahawka]

About a week ago I bough a new rbta. He is looking healthy, eatting well and my clown just recently hosted it.
He is about 5-6 inches in diameter during the day with tenticles around 3 inches long. However, my concern is at night the bubble tip contracts to a tiny size. Maybe 2 inches and the tenticles are only 1 inch long. The contraction will happen over a span of 1 hour once my white lights is turn off. And in the morning he would expand again.

Is this normal behaviour ? Especially to that extreme.