Pistons powered from piston arm

An upward-facing piston with a block on its pushing face, when powered, will extend and move that block by one, and retract when unpowered, as it should. However, if that block is a Redstone Block, the piston does not depower, maintaining an extended position for so long as the redstone block remains.

Do note that does not happen on any other facing, only when pushing upwards.