Chest breaking and harvesting, contained items disappear

on moving chests, normally items contained appear all over the same location as a mess. occasionally items don't appear, no chest or items. I have done local search to see if they appeared behind walls or below floors and have not found them.
this does not happen every time.
may be connected; mining or harvesting, produce no drops.
. . example; fully grown wheat normally drops wheat and seeds. no drop
. . . . animals and villagers locked out of area so they can't take them.