Bottom texture of leaves disappears when leaves are placed on top of certain bottom copper slabs

Summary:
When leaves are placed on top of certain bottom copper slabs, the leaves' bottom texture disappears.

List of slabs:

• Exposed Cut Copper Slab
• Weather Cut Copper Slab
• Oxidized Cut Copper Slab
• Waxed Cut Copper Slab
• Waxed Exposed Cut Copper Slab
• Waxed Weathered Cut Copper Slab
• Waxed Oxidized Cut Copper Slab

Steps to Reproduce:

1. Place a slab from the list above
2. Place a leaf block on top of the slab
3. Look at the bottom of the leaf block

Observed Results:
The bottom texture is not rendered.

Expected Results:
The bottom texture should be rendered.

Screenshots: