We have a 2021 303BH Prowler travel trailer. We have been camping in it 3 times so far. I have noticed the black water tank filling up faster than normal usage. When I go to dump the tanks I noticed the grey water tank has barely any water in it. The black tank is always full. I have a portable tank that I have to take with me to dump the tank while at campsite during our trip. Last week I had a suspicion that the sink drained into the black water tank. I ran a water hose in the sink for a little while and turned it off. I checked the grey water tank and it was empty. So I checked the black water tank and it showed 1/3 full. So I opened the toilet valve and looked in there and it was 1/3 full. I called my dealer and they said that Prowler is now plumbing the sink water into the black water tanks to prevent solid buildups in the tank itself. I contacted Prowler on Monday thru email and asked them if this was true and I have not heard back from them yet. It makes logical sense but I have owned several campers and have never seen this type of plumbing before. They also have the grey water and black water tank stickers wrong on the outside of my camper. And yes I know which one is the black water tank and which one is the grey water tank. The shower, bathroom sink, and kitchen sink is supposed to drain in the grey water and the toilet drains into the black water tank. I do know my campers but this has me puzzled and just would like some type of solid confirmation.