Some materials render black on Iphone 6 series phones

Some materials are not rendering on iphone 6 series devices. They will render completely black on one device but not others in the same series. Replacing the material with a basic material renders on all, though.

The material texture samplers do not exceed 5 of the 8 available. Licensee is reporting that problem does not reproduce on Iphone 5s, 7, iPad Airs, or the Mini (2-4). The iOS version of the phones that are broken for the SE and 6 are using OS 9.3.5 which is consistent with the one that is causing an issue for me below in my test.

IPA from 4.14 build: [Link Removed]

Tested with:
Broken: 4.13.1 binary CL-3142249
Broken: 4.14 Dev-Rendering CL-3151290

Iphones tested with:
Working: Iphone 5s OS 9.3.3(13G34) - asset# - 5065
Working: Iphone 6 OS 8.0.2(12A405) - asset# - 4989
Broken: Iphone 6S OS 9.3.5(13G36) - asset# - 6240

1. Open Test Project
2. Deploy to Iphone Device (Asset #: 6240 reproduces)

Results: Iphone renders the object black on some devices

Expected: The material should not render black.