Hi !
So I’ve been creating a simple dissolve shader. Basically this use a mask referenced in a material function :
I created a material using this function, nothing special yet. But here comes the problem :
In blue, you can see there’s a position sets by a Material Parameter Collection. The MPC is referenced in a BP where a lot of values can be changed such as the Position. The whole thing create a spherical dissolving shader. But when you try to duplicate the BP, only the selected one is dissolving the world. And the issue is that I want to dissolve many times at different places. My programmer and I were trying to solve that and came to nothing except discovering that the Position in MPC was the problem, because all the duplicated BP created well a dissolving shader but the center of the sphere were at the selected BP giving impression that there is only one shader and the others not working.
Even in PlayMode it don’t work. And creating a dynamical material instance too (or we’re using it wrong)
Here’s the reference in the BP.
I can provide any screenshots if requested. I really tried to explain as well as possible, hoping somebody will help 
Thanks by advance !