Create SSRS Report from Custom Workflow

CRM2016  On-Premises

I have spent hours on this and need help understanding what the real issue is.

I created a SSRS repot in VS2015 and uploaded it into CRM and published it for external use

I crated a workflow in Vb.net to call the report and create a PDF via a web service.

In CRM ( signed on as a domain admin ) , I execute the workflow but always get an error in reporting services log 'User not found' ( log below )

1. the report is in fetch xml

2. logged into Reporting services as Domain\Admin , I can execute the report fine

3. logged into CRM as Domain\Admin  I can ruin the report fine from the reports area.

4. The workflow was generated by vs2017 but on a different domain. The web service connects using Domain\Admin credentials and can be previewed in VS with he correct data 

I'm at a loss as to what or where the issue is 

The error is 

Microsoft.Crm.CrmException: An unexpected error occurred.
Microsoft.Crm.CrmConfigObjectNotFoundException: User Was Not Found ---> Microsoft.Crm.Reporting.DataExtensionShim.Common.ReportExecutionException: An unexpected error occurred. ---> Microsoft.Crm.Reporting.DataExtensionShim.Common.ReportExecutionException: User Was Not Found