Following article states about behavior of Group by and Sort functionality on Reports.
- Go to View / Run under Report
- Click New
- Type: List
- Table: Incident
- Group By Configuration Item
- Add Configuration Item to the 'Selected' column slush bucket
- Condition: Configuration Item 'is not empty'
- Sort field: Configuration Item 'Z-A'
- Run Report
Resulting List is A-Z.
Currently this is expected behavior of Platform where group by and Sort function does not work together on reports.
This issue is discussed under - PRB620124