Skeleton heads generated in the ancient cities have incorrect block state

The skeleton head (skull) is generated incorrectly in the ancient cities, the block state visually shows that the head is placed on the wall side, however, the outline tells that it is placed on the top of the block below it.

How to Reproduce
1. Find an ancient city, and then the barrack structure.
2. Find the skeleton head inside.

Observed Result
The skeleton head is generated incorrectly on the walls instead.

Expected Result
The skeleton head is generated correctly on the top of the block below it.

Incorrect generation:

Correct generation (on Java):