cannot create graphs from graph prototype if you don't use any LLD Macroses in Graph name:
I don't need really to use macroses in graph names, since i know that there is always only single item that would be discovered (physical memory).

Cannot create graph: graph with the same name "xxx" already exists from LLD.

So no graphs at all: ,despite its the very first and only item from LLD.

Items and triggers are created though without any problems.