I would make sure you have your trigger bar spring properly seated in the correct locations. It's probably possible to reinstall it improperly and still get trigger response.
now thats from a 226 but i imagine its the same for a 220, and Im not sure how you could install it wrong, but I've seen crazier things happen. my guess is that somehow the spring is somehow over seated into the mag well.
another thing you could do is to inspect your mag's, look for scratches or excessive wear, that could point you towards your hang up.. hope it helps