Bamboo fence gates don't have a bottom texture (or it's missing)

Bamboo fence gates don't have a bottom texture (or it's missing)

Steps to Reproduce:
1. Place 2 blocks of any kind (one on top of another);
2. Place a bamboo fence gate;
3. Break the blocks under it;

4. Look under the fence gate.

I attached a screenshot of the bottom of another fence gate as reference!