Expedition

I do not know if this is fully a bug or if I'm missing something? I am laying down the bombs with the circles around the flags that should have chests under them. I have noticed a few times that nothing will appear from these areas at all. No chest, no monsters, nothing. I do not know if this is an intended feature or if it is a bug so figured I would post it just in case.

bug report reference number: 3,098,211,980