These things require perfect water, (nitrates below 10, no nitrites, and no ammonia). They require intense lighting - think under radions, a Kessil a500x, MH, etc. They require good water movement over the top. Excellent and stable salinity. They will care about your trace elements, alkalinity, and PH must be solid with minimal day and night swings.
Take all that and factor in the fact that they can can take weeks-to-months to die and that it was probably smuggled in on an international flight from overseas.
These anemones should only be kept by a select few who have some level of knowledge, instincts, and experience and kept as rescues. The rest of us should stop buying them so that it no longer becomes profitable to import and sell them.
I’m tired of the “yeah but I kept one in a leaky shoebox and the only light I used was a lightbrite with 50 purple and 20 red pegs and I kept it alive for 10 years back in the 80’s.”
These are not suitable creatures for home aquariums in the same way a penguin, raccoon, or cheetah is a good house pet. Quoting anecdotes and YouTube clips of cute fuzzy lions playing with kids isn’t proof of success either.
Go out and throw a couple thousand dollars of equipment and life support at your tank or find someone locally who can or has experience.
Also factor in that the specific animal’s needs will also vary and there are so many factors to consider and questions you will never have answers to unless you find the poacher who scooped it up and sold it.