Reproduction steps:
1. Open the attached '980122.zip' project.
2. Build and run the 'New scene' using an iOS device.
- Notice, that screen is covered with black squares.
- Objects have more squares. Skybox - less.
- Actual/Expected behavior screenshot attached.

Reproduced with:
- Metal(iOS)

- iPad Pro 10.5” iOS 10.3.3
- iPhone 7+ 10.3.2
- iPad Air 2 iOS 8.1

- 2018.1.0b1
- 2017.3.0p1
- 2017.2.1f1

Not reproducible with:
- macOS(Metal)
or
- GLES
or
- iPad Mini 2 iOS 9.2.1
or
- 2017.1.3f1

Note:
Color Space and Color Gamut doesn’t have impact on this case