Using "Region" filter has no effect on the data displayed in "Reporting Rate and Timeliness" table (see screenshots).
1. Go to "Reports" -> "View reports" -> Stockout
2. There should be some data available - if not:
Create, Authorize and Approve a requisition with at least one product (if there is no previous requisition data)
Run processors groups on the NiFi, so the data will be fetched to reports
3. Select any region in "Region" filter
The data in table "Reporting Rate and Timeliness" is filtered