Ruined portals spawn in villages, causing the village to overlap the ruined portal. Since ruined portals are like lava lakes, and water/lava lakes don't spawn in villages, it is expected for ruined portals to not spawn in villages.
To reproduce, use the seed 4505389494053008000 and run the following command:
/tp @p -1181 66 -1270Linked issues
is duplicated by 5
MC-193740
portals can spawn in desert village
Resolved
MC-216518
Overlapping Structures Generation
Resolved
MC-241161
Ruined Nether Portal spawns inside Village on Amplified world
Resolved
MC-241460
ruined portal spawn in a village house
Resolved
MC-299208
Ruined portals and village houses can generate on top of each other
Resolved
Relates to MC-125004