when you say your parimeters are fine, whats fine? whats your
ammonia/nitrites/nitrates? the tank is so new, im wondering if you are having an ammonia issue..how did you cycle it so fast? are you still using stability? if so, its giving you false readings as thats not aquatic bacteria and will not cycle a tank
if at all possible, find some prime or ammo lock + to do daily water changes to see if that helps them ....you will have to do every other day water changes even after the tank is cycled as its severely overstocked and the ammonia can climb fast.....
I hope things get better!