Fix for Empty login_hint Parameter on External Identity Providers Requests

What's Changing:

We are fixing an issue where Auth0 was including an empty login_hint query parameter when redirecting users to external identity providers. Going forward, login_hint will only be included in the authorization request when a value is actually present.

Why This Matters: Some external OAuth providers strictly validate request parameters and reject authorization requests that contain empty parameter values. This caused authentication failures for customers whose upstream identity providers do not tolerate empty login_hint values — particularly in scenarios where customers do not control the external IdP and cannot modify its validation behavior.

Rollout Timing: This fix will be rolled out progressively over the next 1–2 weeks.

Action Required: No action is required from customers. If you previously implemented a workaround by overriding connection parameters to suppress the empty login_hint, you may optionally remove that override after confirming the fix is active in your environment.