Group node instancing? I am trying to get Group nodes to work in the Shader Editor. All of the documentation and blogs I've seen say that Group nodes are instanced. I.e. if I create a Group node, it will share all parameters with other identical Group nodes in the .blend file. But that's not what I'm seeing. Group nodes are not instances, parameters are not shared, and I'm left wondering if I've done something wrong.
I create a Group node with CTRL+G
I create another copy of that same Group node with the Add menu
I expect the two Group nodes to be instanced, but they aren't. I change parameters on one of them, and it does not affect the other.
Please help.
This dropdown specifies the Node Tree to be linked within.

Check that both of them have the desired tree.