Megascan bridge plugin break material function

Hi Guys, I’m suffering from a weird problem.
I got some content from market place and
Optimised Glass Shader posted by Calvinatorr | blueprintUE | PasteBin For Unreal Engine 4
This one. There is a Material Function called Baselayer_SF

However, afterI install megascan bridge plugin and import an asset through megascan bridge. A mysterious bug happends: The material function is gone. I opened other project which uses this material blueprint and the Baselayer_SF function is gone as well. Even the projects that uses higher versions of the engine are suffering from this bug.

More material function is suffering. I.e, the stone boulder plugin. A material function loses its file(reference) and cause the material malfunction.

Does anyone have an idea of what is happening?

Is the customm Material Function file still present where you created it?