I thought about this aswell but I didn't change anything about the habitat and they only started fighting recently.is it possible the habitat is too small thats the only idea i can think of
I tried this and it worked out. So I think as you said this is a bug where the animals in the trade center are still registred in the habitat.click on the habitat barrier and see if your trade centre bears are still registered in the habitat but greyed out, it's a bug (or an unintended consequence of their mechanism). fix is to move them for a moment to a temporary habitat and back to the trade centre.