I have a Hudson River Chatham Pellet stove. Has been working fine for years - recently replaced the burn pot and firebrick and worked well for the past 2 months. However, over the past 2 weeks, about 1/8 of the pellets coming down the shoot have started to flip past the burn pot and into the bottom of the stove. Any thoughts on why? Firebrick is flush with the pellet shoot and the new burn pot is exactly same as the old one... Thanks!