Can u see a black rubber seal around your bottom vent? Maybe I got lucky as mine is airtight. I can see the seal budging out from being tight. Guess easiest way to check how much airless u have us to close off both vents. If it still burns, you're not sealed. I've read on other forums that people put a bead of silicon around the bottom vent.
Vision Classic Kamado, Vision Classic Kamado Kub, UDS, Weber Summit Platinum D6, Weber Performer, & Weber Smokey Joe