Node.Inputs count does not match what is visible

[EppuSyyrakki]

Setup: An abstract TreeNode class inherits from XNode.Node and has a method that uses the Node.Inputs property. The abstract class has no inputs of its own, but Sequence : TreeNode class has a dynamic port list with 2 elements connected.
edit: There is no custom editor code anywhere.

Problem: When debugging Node.Inputs.ToArray() inside the inheriting class, we see the port count is actually 3. The first port is a non-dynamic port without any connection. I have no idea where this is coming from. Other classes inheriting from TreeNode that have a (single) non-dynamic input port display the correct port count.

Any idea what is happening?

P.S. Excellent work. XNode is present in some form in almost every project I've worked on.

[Siccity]

Could you try getting the names of the ports? Maybe that will shed some light on the issue.
Dynamic Port Lists name their ports [fieldname] [index], but perhaps it also added an extra port for the array itself that is just named [fieldname]