comparator doesn't update when powered by a cauldron trough a block and the cauldron gets pushed with a piston

how to recreate: (like shown in the pictures)
1. place a solid block, with a cauldron adjacent to it, and on the opposite side of the block a comparator facing away from the block.
2. push or pull the cauldron with a piston
3. you will notice that the cauldron doesn't update.