Custom Post Type `menu_order` always set to 0 when saving as JSON

Describe the bug
Whether manually exporting as JSON, or using the acf/settings/save_json filter, menu_order always reverts to 0

To Reproduce
Steps to reproduce the behavior:

1. Go to Post Types
2. Create new Post Type, and set custom Menu Order under the Advanced > Visibility tab
3. Save via filter or manually export JSON on Tools page
4. See menu_order is 0, although UI reflects correct value

Expected behavior
JSON Should 100% reflect what's stored in the database.

Code
Straightforward filter usage based on docs:

$ACF_CUSTOM_SAVE_PATH = './acf-settings';

function acf_save_json($path)
{
    global $ACF_CUSTOM_SAVE_PATH;
    return get_stylesheet_directory() . $ACF_CUSTOM_SAVE_PATH;
}

Version Information:

• WordPress Version: 6.3.1
• PHP Version: 8.0.30
• ACF Version: 6.2.1.1
• Browser: N/A

Reproduce the issue from the Post Types UI by setting a custom Menu Order, then save through the Tools page and through the acf/settings/save_json filter. Compare the stored value with the exported JSON and verify that the custom post type's menu_order is preserved rather than becoming 0.