The problem is that you are referencing 'Port1', and 'Port1' is going to be defined somewhere else within your workflow. And within that definition, you are assigning which node to use.
A quick fix for this, is to remove 'Port1' and within its place choose the three dots on the port field. From the pop up window choose 'Filter ports by cluster, node, and name' Then you can fill in the fields on the right to what you are looking for.
The other method is to find where you are defining 'Port1' in your workflow, and change the same parameters from that location.
I hope this helps. Let me know if you need any clarification.