Android Do not Disturb (DnD) permission in managed profile

I have the following problem:

My app is distributed over an MDM system and runs in Android for Work. In certain situation, the app must temporarily terminate the DnD mode. To achieve this, the user must grant the DnD permission when the app is started.

So far so good. If I install the app in the unmanaged area, the app shows up in the list and the permission can be granted without any problems. As soon as the app is distributed via an MDM system, the app no longer appears in the list and the permission cannot be granted. All authorizations have been granted in the MDM system. As an example, I have distributed the Google App over the MDM system. This app appears in the list.

In the Manifest I have set the following permission:

<uses-permission android:name="android.permission.ACCESS_NOTIFICATION_POLICY" />

When the app is started, the following code is executed:

NotificationManager nm = (NotificationManager).getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);
if(android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M && !nm.isNotificationPolicyAccessGranted()) {
  Intent intent = new
  Intent(Settings.ACTION_NOTIFICATION_POLICY_ACCESS_SETTINGS);
  startActivity(intent);
}

The problem only occurs with DnD permission. All other permissions such as overlay permission, are displayed without problems.

I hope anyone can help me.

According to Android documentation: NOT POSSIBLE

Users can grant and deny access to Do Not Disturb configuration from here. Managed profiles cannot grant Do Not Disturb access.