Hoppers placed using /fill or /setblock with the tag "["facing_direction"=1]" get placed without a spout whereas hoppers placed with anyother value for "facing_direction" or by hand do. By testing this theory, I figured that for hoppers, if placed with "facing_direction" set to 1, it attempts to place the hopper supposedly with its spout facing up. I'd imagine the way to fix this is by changing the "facing_direction" variables for hoppers from numbers 0 through 5 to north, east, south, west, and down.