Here's an odd one: I bought a couple of Rise RA-140 drop in triggers for a couple of AR builds I did using Anderson lowers. Install went fine using KNS Anti rotation pins as they recommended. The one I've been using most ran and function checked fine for the first few hundred rounds but now it has developed a distinct trigger slap on reset and will go on safe with the hammer forward. For SnG I checked the tension pins on the sides of the unit and they were quite snug, snug enough to ensure the unit is tight against the pins. I pulled the safety and there's no considerable wear on either the safety nor the trigger, and this happens during a manual function check with a few different safeties I have here. I contacted Rise and will post their response.