When the classic programmer resource pack is used, the chests seem to become a bit confused and mirror their textures. This affects all four chest types introduced before 1.14. The Shulker Boxes' graphic for the lower shell is moved to the underside of the box with a blank texture taking its place, the "voids" that are part of the other chests' interiors have been relocated to the tops and bottoms of the chests, and the Eye of Ender on the front of the Ender Chest is now on the back of the chest. The attached screenshots show these mix-ups as they appear in-game.

No mods were in effect, just pure vanilla Minecraft.