Unknown error using Groovy/REST API to move data from FCC to ASO Reporting cube

Summary: Attempting to write a Groovy/REST API script to facilitate data entry made within an FCC application to be moved, On Save, to an ASO Reporting application, setup as a HyperionPlanning POD. Experiencing issues within the ExportDataSlice step which appear to be associated with a bad sign-on handoff. This has been successful for Gen1 customers but as this is a Gen2 customer, the same setup does not appear to be working any longer.

Content (required):

-This instance is a GEN2 environment and therefore does not have a Domain, only a Tenant. Previously, with Gen1 environment the Domain.UserName was required when setting up this connection. That did not work for this Gen2 Customer connection.