Why won't the excavation site for Mysterious Part B appear?
I am trying to find https://xenoblade.fandom.com/wiki/Mysterious_Part_B to complete https://xenoblade.fandom.com/wiki/The_Riddle_on_the_Wall quest. According to the Wiki, the part should be located in a buried treasure chest in the middle of the Brionac Occupied Zone in the Empire of Mor Ardain. I've gone to the spot https://youtu.be/daznyn2XdK0?t=563 where it should be buried but there's no excavation site.
Why isn't the excavation site for Mysterious Part B appearing?
The excavation site for Mysterious Part B won't appear until you've found and deciphered https://xenoblade.fandom.com/wiki/Mor_Ardain_Murals .
To reach the Mor Ardain Murals, fast travel to Empire of Mor Ardain > Alba Cavanich > Nharil Central Plaza. Turn right and climb two sets of stairs to the roof. Walk north until you reach a set of boxes to access the roof. Head back south towards Hardhaigh Palace and use another set of boxes to get over a railing. When you get to the end, jump across to the building straight ahead. Fall down to the left to find the mural next to a ladder.
Once the mural has been deciphered, the excavation site for Mysterious Part B will appear. If you have Riddle on the Wall as your active quest, the chest location will be marked on your map.