Sorting type flags in `navigation` option not working

[silllli]

Description

I have a pages section where I set sortBy to status desc title SORT_LOCALE_STRING. I use the same value for the sortBy property of the navigation option of the child page blueprint. In the pages section, sorting works as expected; when using the arrow navigation of a child page, the SORT_LOCALE_STRING flag is ignored, resulting in a different sorting.

Expected behavior
Sort the pages the same way in both places.

To reproduce

1. Create a parent page blueprint with a pages section

# parent.yml

pages:
  type: pages
  create:
    - child
  sortBy: status desc title SORT_LOCALE_STRING

2. Create a child page blueprint with the navigation option set

# child.yml

navigation:
  sortBy: status desc title SORT_LOCALE_STRING
  status: all

3. Create a child with a title in quotes title: “Example page”
4. Observe the different sorting order between the pages section and arrow navigation of the child

Your setup

Kirby Version
5.3.1

Your system (please complete the following information)

• Device: MacBook Pro
• OS: macOS 26.3
• Browser: Safari
• Version: 26.3

Additional context
My locale is de_DE.utf-8.

[afbora]

I've tested and couldn't reproduce it. Works as expected order. Here my env:

config.php

<?php

return [
    'debug' => true,
    'locale' => 'de_DE.utf-8',
];

parent.yml

title: Parent

sections:
  pages:
    type: pages
    create:
      - child
    sortBy: status desc title SORT_LOCALE_STRING

child.yml

title: Child

navigation:
  sortBy: status desc title SORT_LOCALE_STRING
  status: all
  
fields:
  text:
    type: text

Could you give us more details or prepare basic kit to testing please?