This has happened several times now, at first I thought it was a random glitch.
Test conditions:
Join a roaring bull adventure as ls (I bought on TO).
Start one ali adventure, I've seen this with ywc and first thief.
Load a general with some ali troops.
In the genral window click the new "send to adventure" button.
The general packs up his tent.
Sometimes he almost gets to the storehouse. Sometimes he doesn't complete packing his tent. Suddenly the general is back in his tent on home island as if nothing happened and does not get sent to adventure.
This seems to only happen when a conventional troops adventure and an ali baba is running. When my rb ls ended I could send to the 1st thief and it worked properly.
Here's video (sorry, taken with my phone, I don't have a screen recorder program handy, recommendations welcome for windows)
https://streamable.com/p8ul7
streamed it's 35 seconds, original is 72MB, no idea what size is streamed.