Ruined Portal Spawns inside The earth while peaking out

I generated a new world in the newest snapshot of the game. I got into creative mode and flought around, until i found something strange. A ruined portal in the overwolrd was generated inside the terrain. The land was at y=72 so it seemed kinda odd. The seed is 7292271799410584914 and when you join the world do /tp @p -445 72 -521.