I think it is pretty annoying when vendors, especially farmers, walk out of range while we are trading, and thereby close down the interface. Can't you please fix this so that interfaces stay open no matter how far away the NPC walks?
Another example of this is Otto near the the eastern gate to Eldevin City. He is very conveniently located for selling stuff we collect outside of the gate, but unfortunately he walks around collecting planks, so If I am not careful to place myself near the center of his path, he walks too far away from me when I am in the middle of transfering items to sell, and the window closes down. It is extremely annoying.