It looks like object entry was turned off during the tunnel construction on the Coastal Waterway parcels in these 4 regions and it wasn't restored ever since. This is not great for vehicles since on a failed region crossing or if you have to stand up and sit again, the vehicle gets returned and this is completely disruptive for automated vehicles. All other Coastal Waterway parcels in the other regions in the area have object entry enabled as these used to as well.