Steps to reproduce:
1. Open the attached project ("ShaderGraph-iOS-Bug.zip")
2. Open "SampleScene"
3. Build and run the Xcode project on a device
4. Tap on the screen changing the cameras

Expected results: Both cameras render the shader
Actual results: The camera with Post Processing checked doesn't render the shader

Reproducible on: Shader Graph 10.4.0 (2020.3.2f1), 11.0.0 (2021.1.0f1), 12.0.0 (2021.2.0a12)
Couldn't test on 2019.4 as the ShaderGraph shader breaks

Reproducible with:
- iPad 9.7" 6th gen (14.4)
- iPad Air 2 (11.0.3)
- iPhone XR (13.4.1)
- iPhone 8 Plus (12.0)

Not reproducible with:
VLNQA00332, Samsung Galaxy XCover4 (SM-G390F), Android 9, CPU: Exynos 7 Quad 7570, GPU: Mali-T720
N/A, Xiaomi - (Redmi Note 8 Pro), Android 9, CPU: MediaTek Helios G90T MT6785T, GPU: Mali-G76 MC4
VLNQA00004, Meizu MX5 (MX5), Android 5.0.1, CPU: MediaTek Helio X10 MT6795T, GPU: PowerVR Rogue G6200
VLNQA00333, Hmd Global Nokia 7 plus (Nokia 7 plus), Android 10, CPU: Snapdragon 660, GPU: Adreno (TM) 512
VLNQA00099, Google Pixel XL (Pixel XL), Android 10, CPU: Snapdragon 821 MSM8996 Pro, GPU: Adreno (TM) 530

Notes:
- The issue doesn't reproduce if Post Processing is not checked on the camera
- Reproducible with iOS
- Not reproducible in Android build, Editor play mode