app/lib/guest.tsx

@@ -28,7 +28,7 @@ export class Guest implements Entity {
 
 export class GuestSerializer implements Serializable<Guest> {
   fromJson(data: any): Guest {
-    return new Guest(data.id, data.name, data.group?.name, data.group?.id, data.color, data.status, data.children);
+    return new Guest(data.id, data.name, data.group_name, data.group_id, data.color, data.status, data.children);
   }
 
   toJson(guest: Guest): string {