I just bought my first slow cooker. I put my food and set it to high. Then after 30 mins I hear a popping noise. I think it s coming from the base not the lid which has no gasket on it. Although I m not sure where it s coming from. I only hear it a few times during cooking. The foid took 6 hours on high. The potatoes were still half raw at 4 hours and they were cut n peeled pretty small with liquids. Do you think it s safe or should I throw it out?