My pilot light in my Jotel GF 370 is fine when the fireplace is cool. After an hour or more of use, when I turn the fire off, the pilot light remains lit but a flame “pops” up from the side of the normal pilot light area repeatedly. Once the fireplace cools down, it stops. It only seems to happen when the fireplace is hot and it does not happen when the fire is lit. Any suggestions as what the issue might be?