We will be updating the game very soon with a patch that should optimize Character navigation. The game used to try to generate navigation only once. This would often result in an inaccurate nav mesh after the world had finished randomizing (or applying the randomized world from any existing game file), and especially after placing new buildings.

This would sometimes result in characters getting stuck in certain places, which could cause nearly irreparable damage to save files if the game data was saved at bad times.

However, in the next version, the navigation mesh will be updated constantly, but only within loading zones around the player. Allies who are sent home (by interacting with them while they are in your party), will try to walk towards home for a while, but will teleport after a short period.
In the older versions, characters sent home would actually try to path all the way back to your sanctuary, which had very mixed results. Forcing them to teleport after a short period should mitigate save file issues, and is necessary now that Navigation only generates within the load distance from the Player.