Hi Andrew, I think that this is not related to version 1185 or a bug. The image that you see in the preview is not going to be the same after applying to the image. You may try working with previews.
however I've never achieved approximate results between previews and RealTime
From documentation:
Note: The process offers a realtime preview functionality (experimental) that tries to generate an approximation of the whole processed image.
Saludos, Alejandro.