falling blocks stay as entity after droping on the halfside of a slab

so you would think that the gravel, sand, concrete powder and hanvil would break when falling onto a half slab but no they stay as entity wich looks funny and they stack as one and all get destroyed except one zhen they finaly fall onto a solid block

i've tested more and the entity break after like 30 sec

its not game breaking or annoying in any way I even find it funny so iI don't mind if it stay but I wan tthis bug to be known at least