Some coral banded shrimp won't bother other inverts. Others are a real terror because once they learn the others make a good meal, they will never stop pursuing them. Coral banded shrimp aren't the fastest predators, but they can move pretty quick for the first few inches, and that's all it takes with those double barrel pitch forks up front.
My CB shrimp catches and eats bristle worms, 2" cleaner shrimp, and has taken the tail fins off several fish. He ignores hermet crabs and gets his butt kicked by my sally lightfoot. If it weren't for the fact he has those beautifull feelers a foot across he'd be served with shrimp sauce. Otherwise, cleaners and fire shrimp are far more beneficial for a tank.
I've had outbreaks of aiptasia before, and found that tanks with high PH
(8.3) and kept with high calcium levels don't seem to promote or will at least stunt their growth. Or, it could be another water parameter that I'm not seeing that's reducing their food source.