Resolved UI material no longer works when scene reloads

I came across a UI blur material in a different forum post shown here: https://forum.unity.com/threads/solved-dynamic-blurred-background-on-ui.345083/#post-2853442

It works fine and all, but I am getting weird behaviour from it (whether it's the material itself or the editor causing issues). What is happening is that I will run my scene using the material in the menu canvas to blur everything behind it. I return to something like the main menu scene and select the same level scene again during the same run-time. For whatever reason now, the menu canvas no longer renders the blur material. It's present and I can adjust the blur radius parameter, but nothing renders for that material.

Has this happened to anyone before?

 

Solved: material was ignore canvas stack order, but setting the blur panel image Z from 0 to 1 resolved the issue where it no longer rendered after subsequent scene loads.