In TranslucencyRendering.cpp, FDeferredShadingSceneRenderer::RenderTranslucency, the following code:
SetupDownsampledTranslucencyViewParameters(RHICmdList, View, DownsampledTranslucencyViewParameters);
Manually updates the view uniform buffer parameters without clearing out the cached view. This later causes the view uniform buffer to not get updated back to the full screen parameters.
This issue cropped up with a UDN customer who was adding a second translucency pass.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-74849 in the post.