I'm interested into seeing your files. Usually our cooking for substance discard unused nodes (and therefore any inputs that is not connected to an output node). It could be that your initial setup result in that configuration and the blend node avoid that.
well, we figured out what's wrong For some reason all additional input maps HAVE TO be connected to outputs in some way - in our case with blend node. For example we have a position map going into a generator but if we put it into Painter there is no input for position map and material gets generated incorrectly. So the…