Enable Instancing Won't Stay Checked

In 5.6 there's a new option for Enable Instancing on some shaders, however on any shader I attempt to use this new feature, the changes just don't stick. I can check it on, but as soon as I click off of a shader, it goes back to being unchecked. I know it's a new feature, so is this a bug or does this mean Enable Instancing doesn't work with those shaders? They're all Substances that this is happening with.

Using 5.6.1p3