The bug
There is a jigsaw block in desert_medium_house_1 that turns into air instead of smooth sandstone upon generation, resulting in a block missing from the floor.
MC-147590
Missing floor block in village/desert/houses/desert_medium_house_1
Resolved
Fixed
4
Alex Gonzalez
Confirmed
Structures
Minecraft 19w14b
Minecraft 1.14.1 Pre-Release 1
Retrieved
Confirmed. Caused by the jigsaw block's "Turns into" field being set to "minecraft:air" instead of "minecraft:smooth_sandstone".