Schedule Multi-Job checkbox on Site Maintenance

Per the product documentation, if Schedule Multi-Job is enabled in Site Maintenance, it allow selection of “Ignore Locks” when global scheduling.

We enabled the setting in Site Maintenance, but the checkbox for Ignore Locks is still greyed out on the Global Reschedule launch screen.

Anyone out there who might be able to explain what we might have done wrong?

Did you get any resolution to this? I have the same question.