Brother, I just started a few months too also loved anemone alot... my tank alone got 5 anemone (2fts tank) 1 sebae xtra big one lolz very healthy kekez the tentancle very sticky ( they say for healthy sebae anemone the tentancle will by very sticky) 3 bta n 1 rocky flower anemone dunno wat kind lolz...
I think u got to check water parameter n lighting. The current is important they like current from my observation. Another important thing to take note is dun overfeed them with prawn meat or anything... they will die from over feeding that is how my first anemone die... but after that no more. kekez learn my lesson. My water temperature is at 27 degree celcius, they do better in colder water. mine all open nicely.
Hope it help u, this is just my own thinking la if anything wrong about it the other expert reefer hope u bros will point it out It will help me too.
Btw I got anemone shrimps n crabs living in my anemone which i feel help the anemone in certain way too kekez. My clown fish also