3ds Max only typically supports single output map nodes, so the Substance2 node, the original Substance node and other similar nodes, such as the OSL node, are actually implemented as a hidden 'cluster' of nodes, with the output selector nodes as sort of hidden nodes. These nodes are always there, even in the case of the normal and base color maps, it's only whether or not they're visible that changes.
The visibility of these can be toggled in the configuration options for the Slate Material Editor. Go to Options, then Preferences, then ensure that 'Hide Single Map Output Selectors' is toggled.
I think in some cases it doesn't like hiding them. There's nothing to do, they're always there, it's just whether you see them or not.