### Steps to reproduce

1. open a Gantt View

2. open the details view of a work package with (i)

3. Begin of the insertionOpen DateEnd of the insertion Begin of the deletion enter a date (Milestone type ticket) using the "Date"End of the deletion popup

4. Begin of the insertionEnter a dateEnd of the insertion Begin of the deletion click "save"End of the deletion in Begin of the insertionany other format than YYYY-MM-DD. E.g. 2024-2-15, or 15 Feb 2024End of the insertion Begin of the deletion the popupEnd of the deletion

5. Begin of the insertionTheEnd of the insertion popup Begin of the insertionwill CORRECTLY parse the entryEnd of the insertion Begin of the deletion closes,End of the deletion and Begin of the insertionshowEnd of the insertion the Begin of the insertiondate that was intended, even when it was inEnd of the insertion Begin of the deletion details view correctly showsEnd of the deletion the Begin of the insertionwrong format.

6. Click "save"

7. The work package will show the correct date, in the format "15 Feb 2024" - _**BUT IT WILL NOT UPDATE.**_

8. _**From there on, no more changes to the work packages are possible - unless it is reloaded ("accept to leave page").**_ Nothing leads to an update, no fields, no subject, no description changes, not even deleting theEnd of the insertion Begin of the deletion enteredEnd of the deletion date Begin of the insertionagain.End of the insertion


### What is the buggy behavior?

* the Gantt list itself shows _**no date change**_

* when the work package is opened anywhere else, the _**date is still missing**_

* _**Reloading the list reverts all changes**_


### What is the expected behavior?

Entering or changing a date should enter or change the date in the actual work package data and never show the change in the detail view unless it was actually saved.
If the work package form shows the changed date, the user assumes it is actually changed everywhere else. 

### Environment information

OpenProject 14.6.1 Enterprise Cloud Subscription

Firefox 131.0.2, Windows 11

**Browser**

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

**Operating System**

* [x] Windows
* [ ] Mac OS X
* [ ] Mobile iOS
* [ ] Mobile Android
* [ ] Linux (please specify distro)
* [ ] Chrome OS
* [ ] Other (please specify)

**Language**

English