My 10wk old corgi, Max is having potty traing issues. He sleeps all night and we take him out first thing in the morning. from bed to the great outdoors. He goes out and does his thing. we're out there for about 15 min afterwards. We come in and in 5-15min he runs down stairs to the door and poops again. We have put paper down there and he ignores it. We put a box with paper in it and he used it once. Any ideas how to break this habit.