SSMS connection failure to reporting services

Hi Xriz, 
Thank you for the update.

Since the Web Service URL (/ReportServer) is returning HTTP 500, the issue now appears to be with the Power BI Report Server configuration rather than SSMS itself. SSMS connects through the Report Server Web Service endpoint, so if /ReportServer cannot load successfully, SSMS connections will also fail. The fact that the Web Portal is accessible, but the Web Service URL does not indicate that the Report Server service is reachable but encountering an internal error during initialization.

As a next step, please review the PBIRS log files and Windows Event Viewer for errors generated when accessing /ReportServer. Also verify in Report Server Configuration Manager that the Report Server database connection is valid, the service account has the required permissions, and the encryption keys were restored successfully after the migration. If accessing http://localhost/reportserver (or the configured HTTPS URL) locally also returns HTTP 500, this would confirm a PBIRS configuration issue rather than a network or VPN routing problem. Sharing the relevant log entries should help identify the exact cause of the failure.

The problem has been resolved. The cause was a custom installation to an alternative path. This resulted in the virtual user attempting to start the service lacking write permissions (more precisely, delete permissions) to the folder containing the service.