### Steps to reproduce

1. Login as admin on QA Edge Begin of the insertion

End of the insertion Begin of the deletion
End of the deletion 2. Go to Administration -> Non-working days Begin of the insertion

End of the insertion Begin of the deletion
End of the deletion 3. Click on +Non-working day Begin of the insertion

End of the insertion Begin of the deletion
End of the deletion 4. Enter the name and the date but don't press Add Begin of the insertion

End of the insertion Begin of the deletion
End of the deletion 5. Begin of the insertionSelectEnd of the insertion Begin of the deletion HighlightEnd of the deletion the date Begin of the insertionwith the mouse (having pressed inside the input and startingEnd of the insertion Begin of the deletion in orderEnd of the deletion to Begin of the insertiondrag) 

6. Move the mouse (while still selecting the text, mouse is down) outside of the popover

7. Release the mouse


End of the insertion Begin of the deletion change it manually

End of the deletion ### What is the buggy behavior?

* The modal disappears Begin of the insertion


End of the insertion Begin of the deletion as the date is still highlighted

End of the deletion ### What is the expected behavior?

1. Modal should stay opened as long as we are not done with updating fields Begin of the insertion


End of the insertion Begin of the deletion

End of the deletion ### Screenshots and other files

<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/52686/content">

### Environment information

**OpenProject installation type**

* [ ] Hosted cloud edition
* [ ] Packaged installation
* What distribution? Begin of the insertion

End of the insertion Begin of the deletion
End of the deletion * [ ] Docker All-in-one container
* [ ] Docker-compose installation
* [x] Other (please specify): QA Edge 12.6.0

**Browser**

* [x] Chrome on Windows
* [ ] Firefox
* [ ] Safari
* [ ] Mobile Safari
* [ ] Other (please specify)