[Link Removed]I think it is because that the "bOnChipSunMask " is false as Distortion activated (MobileShadingRenderer.cpp line 378), the "UseFetch" is true as the Android device support shader framebuffer fetch (PostProcessMobile.cpp line 994), the color will be got using FrameBufferFetchES2()(PostProcessMobile.usf line 114), and it will get black color.
I think the "UseFetch" should be checked by "bOnChip" value instead of "GSupportsShaderFramebufferFetch".
1.Create a translucent material and give the refraction input a value.
2.Assign the material to a mesh in the scene.
3.Enable DOF with GaussianDOF method.
4.Build a Android apk and launch it in an Android Device.
The screen will be black.
I upload a sample project to reproduce.
There's no existing public thread on this issue, so head over to AnswerHub just mention UE-68431 in the post.