Steps to reproduce:

1) Download attached project and open in Unity
2) Make sure Graphics API is set to Vulkan
3) Build and Run project on a device
4) Make sure "Use pre-defined effects" enabled (should be selected by default)
5) Select effects in that order: Bloom, Ambient Occlusion, Grain, LensDistortion
6) Press on "Run!" button
7) Watch the benchmark and notice screen distortions when Ambient Occlusion effect is activated

Expected result: No screen distortions when Ambient Occlusion effect is activated (check attached image "expectedpixelc.png")
Actual result: Screen distorted when Ambient Occlusion effect is activated (check attached image "actualRazer.png")

Reproduced with:
2018.2.0a8, 2018.2.0b1, 2018.2.0f2, 2018.3.0a3, 2018.3.0a4
I wasn't able to check with 2018.2.0a1 - 2018.2.0a7 because of errors in the Console window

Not reproduced with:
2018.1.8f1

Devices under testing:
Reproduced with:
VLNQA00006 Samsung Galaxy S7 (SM G930F*), OS:7.0, CPU:arm64-v8a, GPU:Mali-T880
VLNQA00052 Xiaomi MI MAX*, OS:7.0, CPU:arm64-v8a, GPU:Adreno (TM) 510
VLNQA00003 Razer Phone*, OS:7.1.1, CPU:arm64-v8a, GPU:Adreno (TM) 540
VLNQA00128 Samsung Galaxy Note8 (SM N950F), OS:8.0.0, CPU:arm64-v8a, GPU:Mali-G71

Not reproduced with:
VLNQA00124 Google Pixel C* Tablet, OS:8.1.0, CPU:arm64-v8a, GPU:NVIDIA Tegra