Hopper problem 2

screenshot describes the issue best. Items are placed in chest on top of hopper to the right, 5 stacks of 4 different items. items flow through the hopper line. only items 1 and 2 will go to a hopper at the bottom, items 3 and 4 travel through to chest on the left.
depending on orientation items 1 and 2 go into different hoppers.