Double chest only deposits to one hopper

When a double chest is placed with two hoppers underneath, and one hopper feeding the double chest, going into two other storage containers (i.e. more chests, furnaces), only one hopper takes from the double chest. When the items are put into the double chest manually it works as normal. Here is a link to a video I made demonstrating the bug: https://youtu.be/BMkyotumB20