So I don't know if its a bug or intended, but apparently Morrow's Peak outpost doesn't count when buying an Ashen Chest Stash.
Pretty much and Ashen Chest or Ashen Key stash activates a voyage where you can find them on the current outpost you are on, but from the looks of it, Morrow's Peak doesn't count and instead sends you to Ancient Spire.
The SoT wiki doesn't really mention this (then again, some of it is barely updated).
