Environment:

- IdP: Okta Preview org (wfpp-ec4b5.oktapreview.com)

- SP: Salesforce Developer Edition

Problem:

When enabling SCIM provisioning on the Salesforce.com app in Okta, clicking "Authenticate with Salesforce.com" opens a popup that shows about:blank and immediately closes without loading a Salesforce login page. This results in the error: "Could not verify the Salesforce administrator credentials."

What was tried:

- Verified API Enabled on System Administrator profile

- Removed IP restrictions in Salesforce Network Access

- Created a custom Connected App with correct OAuth scopes and callback URL

- Relaxed IP restrictions on the Connected App

- Enabled "Allow OAuth Username-Password Flows" and "Allow Authorization Code and Credentials Flows"

- Changed Instance Type from Sandbox to Production in Okta

- Added Custom Domain in Okta General settings

- Tested in both Edge and Chrome

- Installed orgfarm_app_1 (Okta's built-in connected app) in Salesforce

Note: The UI shows a green "API is authenticated" banner simultaneously with the red error, suggesting a state conflict.

Suspected cause: Compatibility issue between Okta preview org and Salesforce Developer Edition OAuth popup flow.