Just had the same issue. I flew to the spot on a Woodland Mansion map on a 1.13 vanilla server with a world that was generated fresh on 1.13. Mansion wasn't where it was supposed to be. I used the locate command at spawn in a creative single player map with the same seed and it gave me the same coordinates for the Mansion. I teleported there and the Mansion generated correctly in single player.
To fix this, since it was on a freshly-explored area I was able to delete the corresponding region files on the server (while server was shut down, just in case). When I started the server up again and logged back in, the Mansion generated correctly.
In case it's relevant, I also had a similar issue on the same server and world with an End City not generating correctly. It seemed to have only generated a small part of the structure that was in one region, and completely missed the adjacent region which held the entire rest of the (massive) End City structure. The same procedure of deleting and regenerating the region file fixed it then too.
The seed is -2261615291186982711. Mansion is near -12448 ~ 5584.
Islam Elnabarawy
Just had the same issue. I flew to the spot on a Woodland Mansion map on a 1.13 vanilla server with a world that was generated fresh on 1.13. Mansion wasn't where it was supposed to be. I used the locate command at spawn in a creative single player map with the same seed and it gave me the same coordinates for the Mansion. I teleported there and the Mansion generated correctly in single player.
To fix this, since it was on a freshly-explored area I was able to delete the corresponding region files on the server (while server was shut down, just in case). When I started the server up again and logged back in, the Mansion generated correctly.
In case it's relevant, I also had a similar issue on the same server and world with an End City not generating correctly. It seemed to have only generated a small part of the structure that was in one region, and completely missed the adjacent region which held the entire rest of the (massive) End City structure. The same procedure of deleting and regenerating the region file fixed it then too.
The seed is -2261615291186982711. Mansion is near -12448 ~ 5584.