[Bug]: Passwordless login (Passkeys) not working on New Login UI

[fcoppede]

Preflight Checklist

• [x] I could not find a solution in the documentation, the existing issues or discussions
• [x] I have joined the ZITADEL chat

Version

I'm using Zitadel Cloud

Describe the problem caused by this bug

When trying to log in using a passkey having configured the new UI, the following error is shown by the login box: "Could not request passkey challenge"

The login works normally when not using the new UI approach.

To reproduce

1. Configure an application to log users in checking the new UI checkbox.
2. Navigate to the login screen
3. Select a user that has previously enronlled a passkey on the device currently being used to test this
4. The error message will show up "Could not request passkey challenge" (screenshot attached)

Screenshots

Expected behavior

The expected behavior is to get prompted to authenticate using the enrolled authenticator (FaceID, fingerprint, etc.)

Relevant Configuration

When inspecting the network trace, a POST request is made to /ui/v2/login/passkey?loginName=... that return a 500 status code.

Additional Context

No response