Wendy's Headstones Ghosts disappear after re-entering world

I do not know if this is a flaw or not, but even after the disappearance of the flowers on the headstones, the ghosts remain, disappearing/appearing when moving away/approaching the headstones, like a pipspook. 
However, when host re-enters the world, they disappear and you have to decorate the headstones again.