I've been coming here to mine for a long time so I have a good feel for the place. I visited yesterday and today and the Ghosts (always tricky here) are now zerging in groups of around 5 or 6 and respawing (what seems) immediately. This behaviour is quite different from the dozens of times I have been here before and it doesn't feel intentional. The challenge level hasn't been increased, it is still 5+ (+ for the named mob), so I think a Dev needs to take a look at the Ghost spawns. There may also be an issue with the Ghost regeneration rate, but this could be due to the quantity of ghosts interacting at one spot and their respawn rate. BTW, the map is also out of alignment here - the arrow is not over the passages.