### Steps to reproduce

_Please write down the steps to reproduce. Try to write down all necessary preconditions (what permissions do you have, are other users involved?). Example:_

1. Create a long markdown list

2. Add some sub items randomly

1. I'm a happy sub item.

3. You'll see that after list item 9 - sub items will break.

4. Step 4

5. Step 5

6. Step 6

1. I'm another happy sub item.

7. Step 7

8. Step 8

1. I'm one more happy sub item.

1. I'm that sub item's happy sub item.

9. Step 9

10. Step 10 Begin of the insertion


```text
End of the insertion Begin of the deletion

End of the deletion 1. Now I'm a sad sub item. Begin of the insertion
```

1.End of the insertion Begin of the deletion

11.End of the deletion Step 11 Begin of the insertion


```text
End of the insertion Begin of the deletion

End of the deletion 1. Me too.  Begin of the insertion
```

End of the insertion Begin of the deletion


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

_Please describe the bug in as much detail as possible. Example:_

* Lists sub-items break when the list exceeds 9 Begin of the insertionitems.End of the insertion Begin of the deletion items. End of the deletion


### What is the expected behavior?

_Describe how the application should behave like. Example:_

1. Markdown lists should not break.


### Screenshots and other files

Screenshot from before Begin of the insertionsubmission:End of the insertion Begin of the deletion submission: End of the deletion

_<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/640548/content">_

### Environment information

_Please check and fill out the following details to help us identify in what versions and distributions of OpenProject the error occurs_

**OpenProject installation type**

* Hosted cloud edition


**Browser**

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

**Operating System**

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

**Language**

_English_