Mix-blending-mode doesn't work on child elements

Hi guys, I am trying to use CSS’s mix-blend-mode “difference” on some fixed position elements.
I found out that I can only do it on elements that are inside the “body” tag.
Any other element that doesn’t have the “body” as the direct parent of it, doesn’t work.
Is this a webflow bug? It should work as long as the class is the same class I wrote in the CSS.

Here is my site Read-Only: Webflow - Terrific Digital