Retro Payroll Flow - Payroll Relationship Group Parameter

I am working on building a Payroll Flow Pattern where a file is imported and used to create an object group through Initiate Data Loader & Generate Data Loader File tasks. Once the Initiate Data Loader task is complete, it then starts a Recalculate Payroll for Retroactive Changes process.

As a part of running that process, one of the parameters is Payroll Relationship Group. I'm trying to use a Post SQL Bind alongside a "Payroll Relationship Group' parameter within the Flow Parameters. In theory, once the Post SQL Bind runs, the PRG should be created and pull the correct Object Group ID - but its not. If I hard code the PRG name in the Post SQL Bind, it works, even if the PRG is being created within the first two steps of the flow.