Material Layers - switches not working

Hello!

I’m currently using the UE4 Environment Prop Master Material from () and everything works fine. I want to use this shader with the Material Layer feature because I need to be able to swap dynamically between two instances of that Master Shader. However, all the Switch Parameters in the Master Shader seems to not work properly… Some switches are set to false by default and they appear to be all disabled in the Instance but all of the options are appearing and being enabled, making the material unusable.

What you see in the screenshot is the most obvious options that are malfunctioning, but pretty much all of the other hidden options don’t work… The only thing I can do is change the textures parameters but they don’t even show up…

Is this a bug in unreal, or is there something that I’m doing wrong?

Also is there a way to blend 2 materials on one mesh without going through the hassle of modifying the Master Material, risking making the material instances parameters super long and difficult to manage? Is it possible to do it through blueprints?

Thank you very much!