navigator.credentials.create returns an empty object

Hello, we trying to develop passwordless flow in the browser, but when we invoke navigator.credentials.create, it resolves an empty object {}.

We acquired options from StrongKey server and parsed them in navigator options as was shown on wwdc20-10670 demo.

An excerpt of source code is below:

Code Block 
{
    publicKey: {
        rp: {name: queryParams.rpName},
        user: {
            name: queryParams.userName,
            id: toUint8Array(queryParams.userId),
            displayName: queryParams.displayName
        },
        pubKeyCredParams: [{type: "public-key", alg: -7}],
        challenge: toUint8Array(queryParams.challenge),
        authenticatorSelection: {authenticatorAttachment: "platform",},
        attestation: "direct"
    }
}

The user is requested to proceed with TouchID/FaceID/etc. and everything looks as expected, but the returned value is empty.

We have tested the flow in the latest Chrome, Safari and Safari for iOS.

Has anyone encountered this behavior as well?