Hi @MitchR;
Sorry for the late reply. We have identified a bug in the Dynamo Connector (Send Node). As you can see here another user is experiencing the same problem.
We are already investigating and trying to solve the problem. In the meantime, you can send data and Linked models from the Revit 2.19 connector.
Can you let us know what Revit, Dynamo and Speckle Connector versions you are using?
Thank you and sorry for the inconvenience.