In a new java world I was playing survival on, I encountered a zombie village but could only see paths, a singular wall and some pumpkins. Interested and wanting to find the village, I checked with creative mode using the same seed: to my surprise I'd found out the village structures other than the path in my survival world hadn't generated when I checked in creative, which did generate the village properly. I then created another creative world with the same seed, only for it to generate only paths and pumpkins again. I checked the settings and I have generation of structures on (everything else is generating as usual), so I can only assume this is a bug. I have been checking the seed a few times and it seems it alternates between generating the village correctly and the village not properly generating.
Since this is the first time I've ever seen this bug occur I am assuming it affects only zombie villages in the current version.
This issue is already being tracked at MC-202186. 🙂