UE4.26 - Translucent material on top of another, causes the one on top not to show, why?

WOW… I’m gonna start using less transparency and more Masking and dithering now! sometimes ocean materials are very expensive, my heavy scenes, lots of assets can drop in UE4 from 125FPS to 90FPS just because of water materials… even after disabling tessellation.

This post turned into a very interesting discussion.