React Native ErrorUtils Global Handler not called

I am using RN 0.61.5, and set my custom error handler ErrorUtils.setGlobalHandler(customHandler);.

export const setGlobalErrorHandler = once(nativeModule => {
  console.log("inside setGlobalErrorHandler")
  const originalHandler = ErrorUtils.getGlobalHandler();
  console.log("originalHandler:", originalHandler)


  async function handler(error, fatal) {
    if (__DEV__) {
      console.log("is dev env")
      return originalHandler(error, fatal);
    }

    console.log("inside setGlobalErrorHandler, is not dev env")


    if (!isError(error)) {
      console.log("is not error type")
      await nativeModule.logPromise(`Unknown Error: ${error}`);
      return originalHandler(error, fatal);
    }

    try {
      console.log("create JS error")
      const stackFrames = await StackTrace.fromError(error, { offline: true });
      await nativeModule.recordErrorPromise(createNativeErrorObj(error, stackFrames, false));
    } catch (e) {
      console.log("met with error:", JSON.stringify(e));
      // do nothing
    }
    return originalHandler(error, fatal);
  }

  ErrorUtils.setGlobalHandler(handler);
  console.log("newHandler:", ErrorUtils.getGlobalHandler())

  return handler;
});

Did a small test by throwing a JS error when a button is clicked, but my customHandler does not get invoked. The app doesn't show an RED color error box nor crashes. I am suspecting that some other places are handling the error. I did implement any ErrorBoundary that catches all uncaught errors