Your Units returned to your Catacombs because one of the following situations occurred while your Units were on the way to the Stash:
- The Stash disappeared from the Map as no one сaptured or attacked it for more than 24 hours;
- The Stash ran out of Resources;
- The Stash was captured by a member of your Clan;
- The Stash you were trying to attack scout became vacant.
In all these cases your Units do not travel back to your Stronghold but are immediately sent to your Catacombs.