Overwriting structure containing signs InvalidArgumentException

When selecting an entire structure (in this case water_room or with_signs) loaded into the world and setting it to air or dirt, Minecraft would crash shortly after with:
java.lang.IllegalArgumentException: Cannot get property bbc

{name=facing, clazz=class dz, values=[north, east, south, west]}

as it does not exist in baq

{block=minecraft:air, properties=[]}

However, after removing the 4 signs from the structure, Minecraft would not crash when I use /fill on the whole structure.

The Data Pack attached has 3 structures: water_room, with_signs and without_signs. water_room and with_signs should be the same.

Game Output Log: https://pastebin.com/ASvPVeCc
Crash Report: https://pastebin.com/rdw3dkW7