Difficulties setting up Postgres in OnPrem Data Gateway

Thanks for the detailed breakdown—sounds like you've already ruled out most of the common issues. Here are a few additional things you might want to check:

1. Gateway Service Account Permissions
   Ensure that the On-Premises Data Gateway service account has the necessary permissions to access the PostgreSQL database. Sometimes, even if the connection works manually, the gateway service might be running under a different context.

2. Connection Encryption Settings
   PostgreSQL may require or reject SSL connections depending on its configuration. Try toggling the "Require SSL" option in the gateway connection settings and see if that makes a difference.

3. Connection String Format
   Double-check the format of the connection string in the gateway. Some versions of the gateway are sensitive to parameters like sslmode, timeout, or even the port number format.

4. Regional Settings or Locale Issues
   Rarely, locale or regional settings on the gateway server can affect how credentials or connection strings are parsed—especially with special characters.

5. Gateway Logs
   Check the gateway logs (located in C:\Program Files\On-premises data gateway\GatewayLogs) for more detailed error messages. They might reveal something not shown in the UI.

6. Try Creating the Connection via Power BI Desktop
   As a test, try connecting to the same PostgreSQL DB using Power BI Desktop with the same credentials and settings. If it works there, it might help isolate whether the issue is with the gateway or the connection config.

Let us know if any of these help—or feel free to share the exact connection string format you're using (without credentials), and we can take a closer look.