A further note on this issue.

When using the command "processrun" we get a dialog box asking us to verify mappings. Here we select the service we require.

This is fine but there is also another tab > "FITTINGS IGNORES", here we see a list of fittings which appears to be the additional Nodes placed on the DesignLine. If we select to ignore these fittings then the DesignLine populates/fills correctly.

Question is.. why are they there in the first place?