Firebase Hosting Authentification signInSuccessUrl not working

I have a problem that after Firebase Hosting Authentification the link to my page (signedIn.html) is not working (Failed to load resource: the server responded with a status of 404 ()).
The authentification itself seems to be working working well, and if I test it on Visual Studio Code debugger, the link to “signedIn.html” is also working, but not on firebase hosting after firebase deploy.
According firebase deploy protocol, all files are successfully uploaded to firebase.

var ui = new firebaseui.auth.AuthUI(firebase.auth());

var uiConfig = {
  callbacks: {
    signInSuccessWithAuthResult(authResult, redirectUrl) {
      return true;
    },
    uiShown() {
      document.getElementById('loader').style.display = 'none';
    },
  },
  signInFlow: 'popup',
  signInSuccessUrl: 'signedIn',
  signInOptions: [
    firebase.auth.EmailAuthProvider.PROVIDER_ID,
    firebase.auth.GoogleAuthProvider.PROVIDER_ID,
  ],
};
ui.start('#firebaseui-auth-container', uiConfig);