You inner shield is not positioned correctly, it needs to be pushed back a bit farther! Make sure it is in the three slots (rear and both sides). You should not be able so see the aluminum cap as I can see from from your picture, it should sit just above and inside the opening, but below the probe part of the thermometer. Also, stand back and look to see if it is level before putting on the top dome. I think that you have it caught on the probe of the thermometer or the front lip of the opening. Take care!