By Placing blocks like the light green wool in the picture and turning autojump on you can always take this jump perfectly so as this jump is used in many jump and runs.. i wonder if that is intentional.
Also it jumps onto a block with a trappdor or carpet on top but not onto two carpets or trapdoors stacke on top of each other.
A simillar thing happens with Snow, you can jump 1.3 layers but autojump only jumps 1.2