### Discussed in https://github.com/apache/airflow/discussions/24548

<div type='discussions-op-text'>

<sup>Originally posted by **don1uppa** June 16, 2022</sup>
### Apache Airflow version

2.2.5

### What happened

I have a dag that starts another dag with a conf.   
I am attempting to start the initiating dag a second time with different configuration parameters.   I it to start the other dag with the new parameters.

## What you think should happen instead

It should use the new conf when starting the called dag

### How to reproduce

See code in squsequent message

### Operating System

windows and ubuntu

### Versions of Apache Airflow Providers

N/A

### Deployment

Docker-Compose

### Deployment details

_No response_

### Anything else

**Work around for now is to delete the previous "child" dag runs.**

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)
</div>
import pytest
from airflow.exceptions import AirflowException, DagRunAlreadyExists
from airflow.models.dag import DAG, DagModel
from airflow.models.dagbag import DagBag
from airflow.models.dagrun import DagRun
from airflow.models.log import Log
from airflow.models.serialized_dag import SerializedDagModel
from airflow.models.taskinstance import TaskInstance
from airflow.operators.trigger_dagrun import TriggerDagRunOperator
from airflow.triggers.external_task import DagStateTrigger
from airflow.utils import timezone
from airflow.utils.session import create_session
from airflow.utils.state import State
from airflow.utils.types import DagRunType
pytestmark = pytest.mark.db_test
DEFAULT_DATE = datetime(2019, 1, 1, tzinfo=timezone.utc)
TEST_DAG_ID = "testdag"
TRIGGERED_DAG_ID = "triggerdag"
DAG_SCRIPT = (
    "from datetime import datetime\n\n"
    "from airflow.models import DAG\n"
    "from airflow.operators.empty import EmptyOperator\n\n"
    "dag = DAG(\n"
    f"dag_id='{TRIGGERED_DAG_ID}', \n"
    "default_args={'start_date': datetime(2019, 1, 1)}, \n"
    "schedule=None,\n"
    ")\n"
    'task = EmptyOperator(task_id="test", dag=dag)'
)
class TestDagRunOperator: