Door/ Pressure Plate one door triggers properly, the other door does not at all

As seen in the image, door on right "clicks" like it is being triggered by the pressure plates, but it will not close. No redstone besides the plates are involved. The behavior is the same using either double half-slabs or single upside-down half-slabs. The Jack-o-lanterns do not seem to make a difference. The door on the left works properly.