Service Connect - Delete Row in Project Task Table

I am trying to write a workflow to delete Checklist Tasks. I am using ProjectService.Update. I am passing Service Connect the Company, ProjectID, and TaskID. I have set the RowMod in the ProjectTask group to the following values:
D
[Delete]
Delete

I found each of these as suggestions here, and in Epicor documentation. In each case, the Workflow completes without error, but the task still exists. Anyone have any suggestions?
Thanks,
Craig