this insert is steel with a cast face and door. The steel and cast are have gasket material in between that I imagine seals up the seam. For a year or so I have noticed a small amount of the gasket material when looking at where the slit where warm air blows out. I noticed today what looks like a little bit more of it today. Stove is functioning fine and very controllable. Does this look like anything of a current or future problem?