Sadsim, that repeated selling from the personal inventory has been around for a while. I don't have either season's or SN, but I have to discipline myself not to go for the repeat selling temptation. If you sell the items that land on the ground then move up or down one level, they will reappear and you can sell them again, repeat the up or down move and this will go on indefinately. To avoid this happening, open up the window to show multiples of the items by clicking on the little triangle in the top left of the inventory item box. If this window is open, the items do not land on the ground when you sell them. Alternatively sell from inventory with the game on slow not paused.