### Apache Airflow version

2.3.3 (latest released)

### What happened

An URL I saved in the past, `https://astronomer.astronomer.run/dx4o2568/home?tags=test`,  has the tag field in the query parameter though I was not aware of this. When I clicked on the URL, I was confused because I did not see any DAGs when I should have a bunch.

After closer inspection, I realized that the URL has the tag field in the query parameter but then noticed that the tag box in the Airflow UI wasn't properly populated.

![screen_shot_2022-07-12_at_8 11 07_am](https://user-images.githubusercontent.com/5952735/182496710-601b4a98-aacb-4482-bb9f-bb3fdf9e265f.png)


### What you think should happen instead

When I clicked on the URL, the tag box should have been populated with the strings in the URL.

### How to reproduce

Start an Airflow deployment with some DAGs and add the tag query parameter. More specifically, it has to be a tag that is not used by any DAG.

### Operating System

N/A

### Versions of Apache Airflow Providers

_No response_

### Deployment

Astronomer

### Deployment details

_No response_

### Anything else

_No response_

### Are you willing to submit PR?

- [X] 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)

"""Mark Dag Blocked."""
        allowed_dag_ids = get_airflow_app().appbuilder.sm.get_accessible_dag_ids(g.user)
        
        selected_dag_ids = {unquote(dag_id) for dag_id in request.form.getlist("dag_ids") if dag_id}
        if selected_dag_ids:
            filter_dag_ids = selected_dag_ids.intersection(allowed_dag_ids)
        else:
            filter_dag_ids = allowed_dag_ids
        if not filter_dag_ids:
            return flask.json.jsonify([])
        dags = (
            session.query(DagRun.dag_id, sqla.func.count(DagRun.id))
            .filter(DagRun.state == State.RUNNING)
            .filter(DagRun.dag_id.in_(filter_dag_ids))
            .group_by(DagRun.dag_id)
        )
        payload = []
        for dag_id, active_dag_runs in dags:
            max_active_runs = 0
            dag = get_airflow_app().dag_bag.get_dag(dag_id)
            if dag:
                
                max_active_runs = dag.max_active_runs
            payload.append(
                {
                    "dag_id": dag_id,