Game mode: [ (Online official]
Type of issue: [ Bug | Other ]
Server type: *[ PvP]
Recent anti mesh changes are preventing building in normal internal areas that were previously buildable. It seems the anti mesh area meant to prevent people from putting things in the mesh is overlapping into intended building areas.
Since the update chests and building pieces that were on or near the immortal structures internal walls are inaccessible when previously they were. Objects cannot be placed and in one upper corner there seems to be an invisible wall or mesh preventing people from walking up to the immortal wall.
In the four corners of the immortal great dam bunker structure, try placing objects off the wall or accessing structures that were placed before 2.4 console update.