The first thing you may want want to try is tighten the gasket. These gaskets get flat over time. You need to remove the inside cover and you will see four bolts, one in each corner. Tighten these down snug, but do not over tighten. You can check these every few years, but at some point you will need to replace that gasket as they get too flattened out to work well.
By the way, I have a new still in the box gasket that I will give you if you need it.
2016 Wildwood 195BH
2009 Silverado 1500