How hot is it running with everything closed tight?
Edit: From the sound of it, once you light the stove you have absolutely no control over it....A very dangerous situation!
(Before you light it each time, as Dirty Harry would say: "You have to ask yourself one question:........Do I feel lucky?"
Seriously, that's not a safe situation
. Do you have a barrel of sand nearby to smother the fire if need be?
The fire is getting air from somewhere. Blow smoke towards the stove & see where it's drawn in & see if you can seal it off better....Don't follow the ash door held with magnets line?? Is there no mechanical mchanism to keep the ash door closed?