Chest Cannot be placed next to Double chest. When there is a double chest, you cannot place a chest directly next to it. This is illogical, because there is no reason for this bug. A double chest is complete, and therefore shouldn't affect the placement of any chest next to it.

In the Screenshot, the double chest is placed on the Blue blocks below it. As the player, you cannot place another separate chest on the Red block. However, you can place it on the green block. There is no logical explanation for this to be a feature, therefore its a bug.

Although you can place a Trapped chest next to it, it would require more resources just to work around a bug.