Incorrect piston behaviour when a block is powered by redstone next to it

When a block diagonally next to a piston is being powered by redstone (being redstone dust, repeater, comparator or redstone block), block update next to piston causes it to extend and get stuck in that position until the next block update. If you remove blocks from right to left (referencing the screenshot "after block update") so you get the same setup as in picture "after block removal", piston gets stuck without anything powering it.