Missing padding for nested menu items in the admin menu

[hytsch]

Steps to reproduce the problem

Create multiple items (a, b, e.g., item list items) in an admin menu.
Create a menu heading item and subordinate the item items to this item heading (situation 1):

• item heading
  -- item a
  -- item b
  Create another sub-item Item Heading below the item heading and place the items (a, b) under it (situation 2).
• item heading
  -- item (sub)heading)
  --- item a
  --- item b

Expected result

Items a and b are displayed indented (padding left), exactly the same as in the situation 1.

Actual result

Items a and b have no padding left and are displayed on the far left.

System information (as much as possible)

j5.2.6, php 8.3

Additional comments