### 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>
"""
    Triggers a DAG run for a specified ``dag_id``.
    :param trigger_dag_id: The dag_id to trigger (templated).
    :param trigger_run_id: The run ID to use for the triggered DAG run (templated).
        If not provided, a run ID will be automatically generated.
    :param conf: Configuration for the DAG run (templated).
    :param execution_date: Execution date for the dag (templated).
    :param reset_dag_run: Whether clear existing dag run if already exists.
        This is useful when backfill or rerun an existing dag run.
        This only resets (not recreates) the dag run.
        Dag run conf is immutable and will not be reset on rerun of an existing dag run.
        When reset_dag_run=False and dag run exists, DagRunAlreadyExists will be raised.
        When reset_dag_run=True and dag run exists, existing dag run will be cleared to rerun.
    :param wait_for_completion: Whether or not wait for dag run completion. (default: False)
    :param poke_interval: Poke interval to check dag run status when wait_for_completion=True.
        (default: 60)
    :param allowed_states: List of allowed states, default is ``['success']``.
    :param failed_states: List of failed or dis-allowed states, default is ``None``.
    :param deferrable: If waiting for completion, whether or not to defer the task until done,
        default is ``False``.