Happens quite a bit depending on design, location of the tank and where the connection to the tank is. I read that some will take the time to level their MH’s at the dump station to try and solve the problem. I don’t worry too much about it except if the next stop is storage. Having a bit of “leftovers” isn’t much of a problem as long as you also have water in the tank to keep things wet (which you should do anyway).
2016 Newmar Bay Star Sport 3004
2015 Jeep Wrangler 2DR 4WD Sahara, Automatic, Hard Top