The hopper only works to place items in the chest if the player shift-clicks onto the chest but if the player places the hopper using a block up and behind the chest the hopper visually doesn't connect and won't deposit items from the hoppers buffer.
Linked issues
is duplicated by 11
MC-6618
Hopper graphics do not update when block is placed near
Resolved
MC-12170
Hoppers look to blocks next to they when a chest is under the hopper
Resolved
MC-6231
2 Hoppers problem
Resolved
MC-6386
hoppers don't connect with chests properly
Resolved
MC-5764
Hopper doesn´t connect with chests (graphic bug)
Resolved
6 more links
This is not a bug, the hopper connected to whichever block face you place it against, and will deposit to that direction; So in this case it'll deposit to where the sandstone is if replaced with a chest.