Scheduled Refresh fails due to missing credentials

Hi all,

I recently set up a new Power BI Report Server (PBIRS) configuration to address performance bottlenecks. Previously, PBIRS, SQL Server, and SSAS were all hosted on the same instance (Instance 1). In the new setup, PBIRS and SSAS are now on Instance 2, while SQL remains on Instance 1.

For authentication, I am using dedicated domain accounts instead of built-in accounts:

• PBIRS_SSRS: Used for PBIRS/SSRS.
• PBIRS_SSAS: Used to connect to SSAS cubes. This connection works as expected.
• PBIRS_SQL: Used for "scheduled refresh" and connects to the SQL Server on Instance 1.

  
  I encounter the following intermittent error during scheduled refreshes:
  
  

  No credentials were found for the datasource.

  
  If I manually trigger a refresh by pressing "Refresh Now," it will succeed, often multiple times in a row, before the error appears again. Additionally, if I open the PBIX file directly, I can refresh the data without issues.

  I have configured SPNs and delegation as follows:

  • SPN delegation for the SSRS and SSAS accounts to Instance 2.
  • SPN delegation for the SQL account to Instance 1.

    I also modified the rsreportserver.config file as adressed by others, as well as adding <RSWindowsNegotiate /> under <AuthenticationTypes>:

     

    <AuthenticationTypes>
    <RSWindowsNegotiate />
    <RSWindowsNTLM />
    </AuthenticationTypes>
    
    

    Any insights on what might be causing the intermittent credential error or additional configuration steps I may be missing?

    
    Thank you for your help!