As I said in another post I am rebuilding an old project and now I found another issue that I guess have something to do with pre-multiplication of alpha. I have a summary screen that is a GUI with a white background with alpha 0.2 to fade out the game behind it, which worked fine before (about a year ago), but now the background is fully opaque when rendered above the game.
In the editor it will only apply on areas of the screen with other gui.
Has something changed around pre-multiplication of alpha in GUI over the last year or so that might explain the behaviour?