I recently did a high heat burn to get rid of some mildew and did so with success. Runined the Gasket on one side when I had to loosen the top with a puddy knife. Recently cooked some steakes. Did a high hear sear at 675, and then cooked at 400 dome temp with grate below gasket line. My question is that I could not get the grill to shut down with the vent closed and the ceramic top on. The next day it was around 150 degrees. Is this because part of the gasket was ruined. I really do not want to have to replace the gasket but if I have to to shut down the grill I will Thanks for the help