We are full time living in our 3850 mb it is a 2018. We have been having a foul smell every time we flush that fills the hole trailer. We have to get it pumped every 10 days but have yet to be able to get the tank filled beyond 2/3 full before the smell is over bearing. Also we get a bad smell coming from the haul closet whenever we flush. I have been adding chemicals and 5 gallons of water every time we have the tank pumped out but still can not get the tank full before the smell comes back