Yes, you are right, this is related with MC-122171. Please, mark as related with that
I think that this isn't a bug, Mojang is working in something with this.
Duplicate of MC-114950
The world was created in 15w3x (I dont know when exactly) but it zone was generated in this version > maybe in 15w33bThe seed: 175338443The coords: 1408 / 18 / -236 (XYZ)
Yes, you are right, this is related with MC-122171. Please, mark as related with that