## Environment

OpenProject Begin of the insertion:

* [x]End of the insertion `17.4.1` Begin of the insertion
* [x]End of the insertion Begin of the deletion +End of the deletion `17.5.0` (current stable) Begin of the insertion
* [x] `dev`

End of the insertion Begin of the deletion + `dev`. The relevant frontend codeEnd of the deletion `watchTopLayer` is the same across all three.

## Steps to reproduce

1. Begin of the insertion End of the insertion Open a work package and go to the Relations tab. Begin of the insertion

End of the insertion Begin of the deletion

End of the deletion 2. Begin of the insertion End of the insertion Under Children, choose Begin of the insertion"CreateEnd of the insertion Begin of the deletion "CreateEnd of the deletion new Begin of the insertionchild".End of the insertion Begin of the deletion child".End of the deletion The create dialog opens. Begin of the insertion

End of the insertion Begin of the deletion

End of the deletion 3. Begin of the insertion End of the insertion Click into the Description field and type `#` followed enough characters that match up with a WP id/content. Begin of the insertion


End of the insertion Begin of the deletion

End of the deletion This affects any CKEditor field shown inside a native `<dialog>`, including the create work package dialog and the edit relation description dialog.

## Current

The reference list opens behind the dialog and cannot be seen or used:

<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/921980/content">

## Expected

The work-package reference list appears above the dialog and can be selected with the mouse or keyboard:

<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/921981/content">

## Workaround

None Begin of the insertion:End of the insertion Begin of the deletion whileEnd of the deletion the Begin of the deletion modal is open. TheEnd of the deletion list is hidden behind the modal and cannot be interacted with. Top-layer stacking cannot be overridden with `z-index`, and content outside the modal also cannot be interacted Begin of the insertionwith.End of the insertion Begin of the deletion with (whatwg/html#9936).End of the deletion

## Notes

The `@` user-mention list is affected the same way.