[1.3.3389] Caravan marker in pen doesn't release animals

[mgb]

If a caravan hitching spot is built in a pen any hitched animals are never released from the caravan spot into the pen.

I'm guessing this is because the animals are already in the pen but they are not free to roam or feed or go their sleeping spots.

A quick free work-around is to deconstruct and then reconstruct the caravan spot.