Subscription changing from ready to not ready - responsive UI issue

A component subscribes to an item, and render when the subscription is ready. When I update the item, the subscription state moves from ready: true to ready: false Why is that? Besides, the update is done in a method that is run by the client and the server, so the client should always have an idea of what things are like.
This seems to be going against the responsive UI logic.

My container looks like:

export default class ItemContainer extends Component {
  getMeteorData() {
    const id = this.props.id;
    const handle = Meteor.subscribe('itemById', id);
    return {
      ready: handle.ready(),
      item: Items.findOne(id),
    }
  }
  render() {
    const {ready, item} = this.data;
    console.log('ready', ready);
    if (ready) {
      return <Item {...this.props} {...this.data} key={this.props.id}/>
    }
    return null;
  }
}
reactMixin(ItemContainer.prototype, ReactMeteorData);

and then when somewhere else the document for this item is updated, the subscription moves quickly to not ready before going back to ready. This is a problem, because this cause the destruction and re mounting of the child component, which is not excepted.