4 Dead zone tiles just spawned right next to each other

vbarraganj14

These 4 tiles spawned right next to each other those two dops were the only pallets from the middle of th stairs left. Once those pallets were gone 1/4th of the map was just empty. I know dead zone tiles are suppose to spawn in the game along with the dead zone tiles with a (sometimes unsafe) pallet also spawn in. But are 4 supposed to spawn right next to each other making 1/4th of the map one giant dead zone? Has to be a bug.