Usually a badly bleached nem can not process light into energy well, so best would be small feedings like mysis 2-3x a week to help regain health.
I recall you had a bleached mag a few years ago; assume you fed it?
mystery grab bag
Any pictures of this mystery grab bag?
Really it might be best to have your own thread as they are different anemone's and you may have different issues, your tank looks fairly new for one.
I'd post your own and give all specs, params in numbers, time running and all that and track it on your own thread so we do not confuse issues, nems, and remedies, success or not