How to reproduce:
1. Open the attached project
2. Build and run on Android device
Result: Cubes are instantiated and NavMesh is baked, however, some cubes are ignored

Reproducible: 5.6.0b3, 5.6.0b10
Not reproducible: 2017.1.0a2

Note: user uses new NavMesh classes which were introduced in Unity 5.6

DUT(reproducible):
LG G5 [LG-H850], Qualcomm Snapdragon 820, Adreno 530, OS 6.0.1
Samsung Galaxy S 5 Neo [SM-G903F], Samsung Exynos 7 Octa, ARM Mali-T720, OS 5.0.1

Not reproducible in Editor, WebGL, iOS (iPhone 6+ iOS 10.1)