[ROS2][Eloquent] WaypointFollower cannot be used from Action Client.

[seanyen]

Describe the bug WaypointFollower cannot be used from Action Client.

  this->_waypointFollower = rclcpp_action::create_client<nav2_msgs::action::FollowWaypoints>(
    this->get_node_base_interface(),
    this->get_node_graph_interface(),
    this->get_node_logging_interface(),
    this->get_node_waitables_interface(),
    "FollowWaypoints");

  bool ready = this->_waypointFollower->wait_for_action_server();

wait_for_action_server never returns, even though I can see it launched.