All of a sudden I can’t get my hearthstone heritage center stone gauge past 300 degrees. Even if I burn seasoned oak. I also used to have a really high draft and it just slowed down all of a sudden. I cleaned out the stove and vacuumed the cats which I usually do every month. Still the same. This is the third year with the stove. I noticed last night the left cat was glowing red and the right one was not red at all. I know it says this doesn’t mean anything usually but the flame was a steady secondary burn all across the top so I would think they both would be glowing. I also checked the bypass door. Looks like it’s closing properly. Here are some pics I took while I was vacuuming them. Any ideas.