Slime blocks missing cullface argument

Slime blocks are missing the cullface argument in parts of the slime.json model file. The game renders faces of the block that it shouldn't, as seen in the first picture. The second picture is using the fixed model file that I have provided. The text in that fixed model file is also below. My fix however, causes another problem which is that the center cube isn't rendered in gui's, item frames, or on the ground as an item. So a different fix would be required.

{   "parent": "block/block",
    "textures": {
        "particle": "blocks/slime",
        "texture": "blocks/slime"
    },
    "elements": [
        {   "from": [ 3, 3, 3 ],
            "to": [ 13, 13, 13 ],
            "faces": {
                "down":  { "uv": [ 3, 3, 13, 13 ], "texture": "#texture" },
                "up":    { "uv": [ 3, 3, 13, 13 ], "texture": "#texture" },
                "north": { "uv": [ 3, 3, 13, 13 ], "texture": "#texture" },
                "south": { "uv": [ 3, 3, 13, 13 ], "texture": "#texture" },
                "west":  { "uv": [ 3, 3, 13, 13 ], "texture": "#texture" },
                "east":  { "uv": [ 3, 3, 13, 13 ], "texture": "#texture" }
            }
        },
        {   "from": [ 0, 0, 0 ],
            "to": [ 16, 16, 16 ],
            "faces": {
                "down":  { "uv": [ 0, 0, 16, 16 ], "texture": "#texture", "cullface": "down" },
                "up":    { "uv": [ 0, 0, 16, 16 ], "texture": "#texture", "cullface": "up" },
                "north": { "uv": [ 0, 0, 16, 16 ], "texture": "#texture", "cullface": "north" },
                "south": { "uv": [ 0, 0, 16, 16 ], "texture": "#texture", "cullface": "south" },
                "west":  { "uv": [ 0, 0, 16, 16 ], "texture": "#texture", "cullface": "west" },
                "east":  { "uv": [ 0, 0, 16, 16 ], "texture": "#texture", "cullface": "east" }
            }
        }
    ]
}