CKEditor Styles dropdown is anchored to page, not the CKEditor itself

Problem/Motivation

When editing/adding a block in layout builder, when you expand the format dropdown list and scroll up/down with it expanded, the dropdown list isn't anchored to CKEditor and moves with the page as it scrolls. Same thing happens with the CKEditor styles dropdown.

Drupal version: 9.2.11
PHP: 7.4.26
MariaDB 10.3.32

Steps to reproduce

1. On simplytest.me, select ‘Drupal Core’ then choose the version 9.2
2. Enable core’s layout builder module
3. Go to the page display (/admin/structure/block/block-content/manage/basic/display) and select ‘Use Layout Builder’ in the layout options’ and save
4. Click the ‘Manage Layout’ button (/admin/structure/types/manage/page/display/default/layout)
5. Click to ‘add block’ and then ‘+ create custom block’
6. Click the dropdown for ‘Format’ and then scroll up/down on settings tray and then on the page - the dropdown should move with your scroll

Proposed resolution

Find a way to absolutely position the dropdown in relation to the CKEditor instead of the page itself.