This is the second time it happens for me in version 1.6.2. After beating An ennemy AI with friendly prisoners, Friendly Lord are liberated after a new dialogue with the player. But if this lord is randomly liberated by some companion party in my army the lord stay forever in this companion party as a simple soldier.
I will join a save right after and you can see the soldier Beasag in the cadugan's party.
I've reported on this issue already.
Afaik there is no solution provided by Bannerlord yet.
There is 2 ways to fix this ->
1. let the prisoner stay in the party of the companion until the companions party is defeat - then that npc will be captured and later on released/escape/ransomed like normal.
2. form an army with your companion, travel to your fief - disband army, then disband the companion lead party - it will now travel to your fief.
Enter your fief - you'll notice that the npc that was your companions companion so to speak is now at the keep and free to go about their business.
Take your companion into the party, take all the troops that was donated into your fief from the disbanded party - and voila things are "reset" so to speak.
I wish they fix it sooner than later, as this is an very annoying issue to say the least, and technically it also gimps your faction as it have 1 less lord to form a party.
I've even seen other lords/kings do it even(in that case the only way for the npc to be returned to normal is by the lord/king to be defeated).
Is the thread I posted it in. As you can see its still in progress.
