It may be coincidental with the April Fool update, but starting on that day I started noticing odd behavior:

– After digging stone/minerals, the stones would not enter my inventory. Shortly after, they will re-appear in the places they were dug from.
– Once, while standing in a location I had cleared of stones, they reappeared and started smothering me. I was able to pull out my pick and re-dig the stone to escape.
– When I see this behavior, if I get out and save the world, then get back in, the last few seconds before I got out are "lost". I am located in a prior spot, my inventory is rolled back, placed torches are off the walls, etc.