It looks like a purple stylophora. Not to confuse with seriatopora which is birdsnest. I have seen people using these names interchangeably which is incorrect. Birds nest have very clear sharp, pointy tips, stylophora have rounded tips. But both of those are stony corals.
If it is completely soft, it might be a finger leather coral (sinularia) although all the ones a saw were yellow not purple.
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