I have a 2018 Chateau 30D. The kitchen sink drains slowly. It is a single sink. I removed the P-trap and cleaned it. I then leveled the RV perfectly. Now if I dump a dish tub full of water it will drain just fine. However, when I rinse the dishes, the water is slow to drain. The vent is difficult to reach as I will have to remove the stove to access it. Appreciate your help with this.