action client stuck waiting on server

edit

I've been trying to write an action file (cpp) using the Fibonacci example as a guide but so far it's just getting stuck on starting the server and i can't quite see why.

#include <stdio.h>
#include <std_msgs/String.h>

#include <ros/ros.h>
#include <actionlib/server/simple_action_server.h>
#include <actionlib/client/simple_action_client.h>

#include <mavros_msgs/SetMode.h>
#include <mavros_msgs/CommandBool.h>

#include <rovexp/ModeAction.h>

typedef actionlib::SimpleActionServer<rovexp::ModeAction> Server;
class ModeActionServer {
protected:
    ros::NodeHandle nh_;

    ros::ServiceClient arming_client_;
    ros::ServiceClient set_mode_client_;

    Server mode_server_;

    rovexp::ModeFeedback feedback_;
    rovexp::ModeResult result_;
    std::string action_name_;
public:
    ModeActionServer(std::string name) :
        mode_server_(nh_, name, boost::bind(&ModeActionServer::executeCB, this, _1), false),
        action_name_(name)
    {
        mode_server_.start();
        ROS_INFO("Mode action server started...");
    }
    ~ModeActionServer(void) { }

    void executeCB(const rovexp::ModeGoalConstPtr &goal)
    {
        ROS_INFO_STREAM("mode experiment started...");

        /*
        set_mode_client_ = nh_.serviceClient<mavros_msgs::SetMode>("mavros/set_mode");
        mavros_msgs::SetMode offb_set_mode;
        offb_set_mode.request.custom_mode = goal->mode_num;

        set_mode_client_.call(offb_set_mode);
        */

        arming_client_ = nh_.serviceClient<mavros_msgs::CommandBool>("mavros/cmd/arming");
        ros::Rate rate(20.0);
        mavros_msgs::CommandBool arm_cmd;
        arm_cmd.request.value = true;
        arming_client_.call(arm_cmd);
    }
};

typedef actionlib::SimpleActionClient<rovexp::ModeAction> Client;
void modeActionClient(uint8_t mode_num)
{
    Client client("mode_client", true);

    ROS_INFO("Waiting for action server to start");
    client.waitForServer();

    rovexp::ModeGoal goal;
    goal.mode_num = mode_num;
    printf("%d\t4\n",goal.mode_num);
    client.sendGoal(goal);

    client.waitForResult();
}

int main(int argc, char**argv)
{
    if(std::string(argv[1])=="-server")
    {
      ros::init(argc, argv, "mode_server");
      ModeActionServer server("mode_server");
      //server.start();
      ros::spin();

    }
    else if(std::string(argv[1])=="-client")
    {
        if ( std::string(argv[2])=="-h" ) {
            printf("Use: rosrun rovexp mode -client @mode\n"); 
            exit(-1);
        }
        ros::init(argc, argv, "mode_action_client");
        uint8_t mode_num = atoi(argv[2]);
        modeActionClient(mode_num);
    }
    printf("done\n");   
    return 0;
}

This is the action cpp file. After running the server and the client I get both "Mode action server started..." and "Waiting for action server to start" so I figure that means the client is getting caught up on ROS_INFO_STREAM("mode experiment started...");. I'm not quite sure why the server is taking so long to start up. I've also attempted the Fibonacci example in link and that works fine.

Ubuntu 16.04 LTS and ROS Kinetic.