Why doesn't my cover fit tightly? Why doesn't my cover fit tightly?5.5 Qt Rival Crock Pot - lid

Question

Why doesn't my cover fit tightly?5.5 Qt Rival Crock Pot - lid does not fit tightly and hot water is bubbling and spitting out of the crock pot making a mess and an unsafe situtation...help! Is this a problem with the model? Is there something I need to do on my end? I tried it with little and a lot of liquid and still happens on both high and low...