I deploy MongoDB replicaset with single endpoint. Want to test connection using simple code to write but write failed by returns '(NotMaster) not master' when i tried to connect to MongoDB using URI "mongodb://serverIP:27017/admin?connect=direct"

```
   rows := db.Database("tester").Collection("test1")
   cursor, err := rows.InsertOne(context.TODO(), json)
   if err != nil

{             log.Printf("%v", err)             continue         }

        id := cursor.InsertedID
```
return message:
```
2019/07/26 13:21:40 (NotMaster) not master
```
But when i create similar function to insert using pymongo, connect using same URI it returns 'no master' for a couple second and then works fine.

```
result = col_ready.insert_one(post).acknowledged
logger("> {1}".format(i, result))
time.sleep(1)
```
return message:
```
2019-07-26 13:25:01,366 not master
2019-07-26 13:25:02,704 > True
```

Did i miss something?