Keycloak on Android app built with Capacitor: keycloak.init() Promise is not resolved

Question

I am using keycloak v 21.0.1 with keycloak-js. I have the following code for keycloak login:

  keycloak.onAuthSuccess = () => {...}
  keycloak.init({
    onLoad: 'login-required',
    pkceMethod: "S256",
    checkLoginIframe: false,
  }).then((authenticated: boolean) => {...})
  .catch(err){....}

When run on web, when a call to redirectUri is received after a successful login, "then" block is called and also onAuthSuccess is invoked. When run on the capacitor app on Android, the keycloak login is shown and the login succeeds. I can see my session in keycloak admin UI. Also, I receive the redirectUrl and the app, configured to activate on the redirect Url, does become active. But "then" block is not invoked and event does not get invoked.