do Google Map Markers have to be added in ViewDidLoad? - ios

Question

This is my code for ViewController.m: So far, I've been loading a list of Map markers from a database in viewDidLoad. I want to add a marker and have it appear on the map, but the marker never shows up until I close the view and open it again.
#interface ViewController : UIViewController <GMSMapViewDelegate, CLLocationManagerDelegate>
#property (strong, nonatomic) IBOutlet GMSMapView *mapView;
#end
- (void)viewDidLoad {
[super viewDidLoad];
// Getting My Location
//Instantiate a location object.
locationManager = [[CLLocationManager alloc] init];
[locationManager setDelegate:self];
//Set some parameters for the location object.
[locationManager setDistanceFilter:kCLDistanceFilterNone];
[locationManager setDesiredAccuracy: kCLLocationAccuracyBest];
[locationManager requestWhenInUseAuthorization];
[locationManager startUpdatingLocation];
NSLog(#"created locationManager");
// Google Map View
_mapView.settings.compassButton = YES;
_mapView.padding = UIEdgeInsetsMake(self.topLayoutGuide.length + 10, 0, self.bottomLayoutGuide.length, 0);
/* Setting Up Markers */
self.mapView.delegate = self;
[self addMarkers];
}
an IB Action is called (and definitely gets called) to add a new Marker, but the Marker does not show up on the map. I've tried this in ViewWillAppear and others, but the marker is not added. I'm starting to think markers can only be added in ViewDidLoad...is this true?
-(IBAction)unwindtoRoot:(UIStoryboardSegue *)segue {
NSLog(#"unwindToRoot");
//[self addMarkers];
CLLocationCoordinate2D position = CLLocationCoordinate2DMake(40.729358, -73.998301);
GMSMarker *marker = [GMSMarker markerWithPosition:position];
marker.title = #"Kopi Kopi";
marker.map = _mapView;
}