Hello, I’ve been running my new Harman p35 insert stove for about a week now. It has been running in room temp mode set at about 68 degrees during the day. Today is the first day I’m seeing a large build up of “material” in the burn pot. I’ve uploaded a photo. The burn pot was cleaned about 24 hours ago. Is this build up normal? If not, any suggestions on adjustments to make? Thanks!