Two Cushions Stack on Same Wool Stair at 50 CPS While Sitting and Looking Up

When sitting on a cushion placed on a wool stair in a vertical column, angling the camera upwards, and using an auto-clicker at approximately 50 clicks per second to continuously place cushions, two cushions may become stacked vertically on the same wool stair block (one directly above the other). They should not be stackable. To reproduce: place a vertical column of wool stairs, sit on a cushion on one stair, look up towards the stair above, and use an auto-clicker (~50 CPS) to continuously right-click/place cushions; observe that two cushions are stacked vertically on the same block.