Copying over most of the content from #29186 because it's the same bug, but this is J4, not J3, and I'm not sure if it's been fixed in J3 in the meantime.

Steps to reproduce the issue

Backend Administration

1. Navigate: Content > Categories

   • Create new category “Test category with field”
   • Save & Close

2. Navigate: Content > Fields

   • Change dropdown from “Articles” to “Category”
   • Create New field “Test category field”
   • Set field to required “yes”
   • Assign the field category to our new category “Test category with field”
   • Save & Close

3. Navigate: Content > Categories

   • Create new category “Test category without field”

Expected result

New category form loads without the custom fields.

Actual result

Custom “Fields” tab loads on new category even though it has been assigned specifically to “Test category with field”

Because the filed has loaded and is required a new category can not be created unless information is filled out in the custom field even though it is not relevant

System information (as much as possible)

Joomla 4.0.5
PHP 7.4.27
MySQLi 10.3.32-MariaDB

Additional comments

Switching categories also has no effect on the custom fields that are loaded. Custom fields only update when the category is saved, but as noted above, you have to fill out any required custom fields before you can save.