### Steps to reproduce

In Begin of the insertionwork pagesEnd of the insertion Begin of the deletion workpagesEnd of the deletion view -> Configure view -> Display settings tab -> Check "Display sums"

### What is the buggy Begin of the insertionbehaviour?End of the insertion Begin of the deletion behavior?End of the deletion

There's no Begin of the insertionSUMEnd of the insertion Begin of the deletion sumEnd of the deletion displayed for the column duration.

### What is the expected Begin of the insertionbehaviour?End of the insertion Begin of the deletion behavior?End of the deletion

Begin of the insertion* DisplayEnd of the insertion Begin of the deletion Please sum it up likeEnd of the deletion the Begin of the insertionSUM of the durations at the bottom of the table.
* In order to display the most accurate SUM for duration the following criteria should be met:
* Parent work packages with manual scheduling should be **included** in the SUM.
* Parent work packages with derivate durations from children should be **excluded** from the SUM.
* Children work packages will always be **included** in the SUM.End of the insertion Begin of the deletion other (custom-)field.End of the deletion

**OpenProject version**

Current 12.3.0 in the cloud