When Forms is configured, which user is used to communicate between Forms and workflow and how do we change that user?

We updated to 10.20 this weekend and most everything went without problems.   However we have 2 forms servers that share the same database.   Our secondary server in the DMZ is able to submit forms but if a workflow is called from the process it goes into a suspend state.   Retrying the suspended step works successfully.   Forms submitted from the primary forms server have no problems invoking  workflow.

The event log on the secondary server states:

 “Message: The remote server returned an error: (401) Unauthorized.

   at System.Net.HttpWebRequest.GetResponse()

   at Laserfiche.Forms.Routing.LFWorkflowService.Execute”

Apparently when we updated our DMZ forms server we used a different user in the configuration.   Which user is used to communicate with workflow and how do we change it?    I am pretty certain it is not the user setup on the forms configuration authentication page.  ( Our connection from the DMZ forms is verified as connecting to the repository server where our workflow is also installed.)

Thanks,

Andrew