Is_activity_scheduled on move from scheduled to unscheduled

Summary:
We implemented a move scenario to Set a property when the order goes from Scheduled to Unscheduled. We put a blocking condition with Is_activity_scheduled is null as we show in the image. But the scenario is also triggered when moving from scheduled to scheduled, from one appointment date to another appointment date. We need to unequivocally recognize that the activity became Unscheduled.

Content (please ensure you mask any confidential information):

We use this to determine in that property Where My Technician Is with an Unscheduled issue that indicates Unscheduled Activity to the client and because of this issue it is not working correctly.