The Woodland Mansion keeps generating weird

The Woodland Mansion isn't generated somehow?
When I do /locate Mansion it gives me ? for the y coordinate.

What I expected to happen was...:
The Woodland Mansion would generate normally

What actually happened was...:
The Woodland Mansion generated very weirdly and/or didn't generate

Steps to Reproduce:
1. create a new world in creative mode in Minecraft version 1.12.2
2. /locate a Woodland Mansion
3. It gives a question mark for the y coordinate