Cobblestone bridging sometimes missing for village paths

Steps to reproduce

• Find a village generating over a cave
• In the new snapshot there should be cobblestone bridging to prevent gravel from falling into caves, however this is sometimes found to be missing
• If you can't find one then refer to the screenshot I took

Example of this:
Seed: -3784431350605944334
Coords: -332 65 692
There are more than one example in this village.