Can remove soil from farm tile without removing the tile, making it passable

If something causes the soil to be removed from a farm tile, that tile will still be displayed, and you can still plant seeds in it, but dupes will be able to pass through it. I'm not sure how to reproduce it in normal gameplay, but  I did see it in normal gameplay. I know for sure that I didn't get it to that weird state with debug mode because I had to enable debug mode in an attempt to reproduce it.  I remember that sand fell and entombed a plant growing out of the farm tile the bug happened to, and I had a dupe dig out the sand, but doing that in debug mode doesn't reproduce the bug.