Villagers get ejected from a minecart when converted to a zombie villager

When villagers are either converted to a zombie villager or cured back into a regular villager, they seem to be ejected from the mine cart I have them in. They end up either half-way inside the block below the cart, or in the case of baby villagers, entirely inside the floor and suffocating. Occasionally they will end up standing on top of the mine cart.