The grave generation previously had some issues actually confirming a grave's selected spawn location was empty. For some reason, in very niche cases the generation algorithm did not catch that the given position was already occupied.

This lead to several issues, like the grave not actually spawning. This is also believed to be the cause of the "unclaimable" graves, where when a graves spawns where another grave already resides, the contents of the former grave are replaced, effectively erasing the grave.

Although I haven't entirely confirmed this, the instance where I tested the occurrence could not be replicated with the new version.