Mountain Aerie "Dead Zone"

Unable to throw objects/hammers into the zone shown. The boss walked into this area and I had to lure it away as my hammers were hitting an invisible “barrier” making them go dead.

Just ran into this during an echo. It seems to be a large area around the bonfires. My abilities like umbral blades and shuriken stop right in front of me. I have to walk about half a screen away to get to the edge of the dead zone.