[0.18.2.0] Heat wave material does not show up on NPC dialogue

I wanted to use the heat wave effect to give a slight warp to an NPC’s dialogue in my condo, but it doesn’t seem to show up in NPC dialogue, even when other materials do

Steps to Reproduce

Make a dialog box with the camera standing in front of a “Heat Wave” Canvas wall.

What I expected to happen

I expected the subjects in the dialog camera to appear wavy, like in this screenshot.

What happened

The heat wave doesn’t appear, and is the dialog camera looks normal.


Notes / Media

I am on running the game through Proton on Linux Mint 22.

Realising now that this should probably be on the nitpicking thread instead. Sorry.