To me it doesn't look like Aiptasia or Majano.
The pattern on the tentacles makes it look like a Phyllangia sp., this would mean it's a stony coral and you should be able to see it retract into a kind of skeleton.
But it could also be one of the thousands anemone species that has a similar pattern. I first thought about Bartholomea sp., but those have more tentacles and ring shaped patterns on the tentacles.