If a hopper has an item (jungle sapling) thrown in and a chest (Full of stacks of 1 jungle sapling) near it, it will ignore the chest and go to the next hopper. However, an item that has been placed manually will go into the adjacent chest.
Linked issues
Comments 2
Er.. no. That does no mention this individual bug. If you would like to add this separate inconsistency to that post, be my guest.
Duplicate of MC-6162.