If a lake generates right under a Plains village's structure, the structure will be partly replaced with air. This may be because of the generation order: Plains villages structures -> Lakes.
MC-140512
Plains villages get cut off by lakes
Resolved
Duplicate
1
Le Duy Quang
(Unassigned)
Unconfirmed
Minecraft 18w48b
Retrieved
there are dozens of duplicates like this. it's a known bug from well before 1.13