Material function not working on MOBILE

I created a material function to fade materials to black if the player is far away from them. I am making a horror game, so his view distance must be limited and dark.

The material fades to black when far away on PC, but it stays orange when launching on my mobile phone (s9 plus). I have a feeling it has something to do with the absoluteworldposition and/or camera position, but I am not sure.

Waiting for some input…thanks