Event from event.nativeEvent.data logs as setImmediate$0.4162155499933975$1

I am trying to pass token and other user details from React Web application to React Native application with Webview (react-native).

When I do

window.postMessage(JSON.stringify(reactNativeObj), '*');

and log the event in React native application with

console.log( "On Message", event.nativeEvent.data );

It is printing the log as

On Message: setImmediate$0.4162155499933975$1

It should print my object instead.

I have tried almost everything and re-read the document https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage but couldn't make it work.

Any help would be appreciated.