I dont know if its a bug but, because of the update when you place a redstone signal in hopper it stops placing items. If you want the hopper to place items in trapped chest, it stops when you are looking in it. I know it is because it is sending a redstone signal, but isnt this the same as if you put a redstone block or torch in front of a piston it wont extend. The same way it shouldnt stop placing in the chest when you are in it. I mean that it doesnt stop when you are powering in front of it, just like the piston.