Pistons can force shulker boxes to pass through solid blocks when activated shorter than 1 tick, for example when the piston activate by observers.

This issue related to MCPE-46746 (which fixed), but this new problem happens only with shulker boxes, and only when the pistons activate in that specific short time. - so you can reopen MCPE-46746 or leave it as a separate ticket.

See picture and watch the video to understand clearly the problem.