Philosophers' Stone Right Click

[Dimpl]

I am playing the Pax challenge map, and when I right-click a block with the philosophers' stone, it changes, but I cannot use this ability again until I fulfill some strange requirement (currently I walk away and come back later, and it will work). Is this a bug, and what is this requirement? (Why can't I use the right-click multiple times in a row on a block)

 

[Bibble]

There is a toggle button for EE. By default, it is "G". This will cycle through the possible transmutations.