HarmonyOS 用户认证模块订阅指纹识别结果的时候，无法得到中间状态的结果

import userAuth from '@ohos.userIAM.userAuth';

const authParam : userAuth.AuthParam = {
  challenge: new Uint8Array([49, 49, 49, 49, 49, 49]),
  authType: [userAuth.UserAuthType.FINGERPRIN],
  authTrustLevel: userAuth.AuthTrustLevel.ATL2,
};
const widgetParam :userAuth.WidgetParam = {
  title: '请输入密码',
};
try {
  let userAuthInstance = userAuth.getUserAuthInstance(authParam, widgetParam);
  userAuthInstance.start();
  userAuthInstance.on('result', {
    onResult(result) {
      console.log('userAuthInstance callback result = ' + JSON.stringify(result));
    }
  });
} catch (error) {
  console.error('auth catch error: ' + JSON.stringify(error));
}