GeoFire query only returns last result - flutter

Question

We are trying to loop through a set of documents in Firestore that are geo based, though the query only appears to be returning the last result and we cannot work out why
Future fetchTasksNearBy(double lat, double lng) async {
debugPrint('getting tasks in location');
GeoFirePoint center = geo.point(latitude: lat, longitude: lng);
double radius = 70; //in km
String field = 'location';
// Reading nearby tasks based on lat, lng parameters
try {
// Collection ref
var collectionReference = tasksRef.where('status', isEqualTo: 'Posted');
var geoRef = geo.collection(collectionRef: collectionReference);
Stream<List<DocumentSnapshot>> placesStream = geoRef.within(
center: center,
radius: radius,
field: field,
strictMode: true,
); // = false includes borderline places
await for (var doclist in placesStream) {
for (DocumentSnapshot ds in doclist) {
GeoPoint point = ds['location']['geopoint'];
_tasks.add(Task.fromDoc(ds));
return _tasks;
}
}
} catch (e) {
throw Exception(e);
}
}