[x] I've searched for any related issues and avoided creating a duplicate issue.
Please give us a description of what happened
When I uncheck the "Show the categories prefix in the slug" option in Yoast SEO (Yoast > Settings > Categories & Tags > Categories > Additional settings), the category slugs become case-sensitive (this is not normal for WordPress slugs).
For example, /tokyo/ works, but /TOkyo/ results in a 404 error, or category 'Abcdefg' would show correctly at mydomain.com/abcdefg/, but mydomain.com/ABCDEFG/ will either 404 or navigate to a different page (that has 'Abcdefg' in the title).
To Reproduce
Step-by-step reproduction instructions
Uncheck the "Show the categories prefix in the slug" option in Yoast SEO
Navigate to a category page
Try the same URL with all-caps
Expected results
All case variations of the slug should navigate to the category page (like the default WordPress behavior)
Actual results
Lowercase only slug navigated correctly
Mixed/Uppercase slugs navigate elsewhere (either 404, or redirected by WordPress)
Screenshots, screen recording, code snippet
If possible, please provide a screenshot, a screen recording, or a code snippet which demonstrates the bug.
Technical info
If relevant, which editor is affected (or editors):
[ ] Block Editor
[ ] Gutenberg Editor
[ ] Elementor Editor
[ ] Classic Editor
[ ] Other:
Which browser is affected (or browsers):
[ ] Chrome
[ ] Firefox
[ ] Safari
[x] Other: Browser does not appear to be relevant here
Used versions
Device you are using: PC
Operating system: Windows 10
PHP version: 7.4.33 (Supports 64bit values)
WordPress version: 6.5.3
WordPress Theme: Custom (also tried with default theme, and the issue persists)
Please give us a description of what happened
When I uncheck the "Show the categories prefix in the slug" option in Yoast SEO (Yoast > Settings > Categories & Tags > Categories > Additional settings), the category slugs become case-sensitive (this is not normal for WordPress slugs).
For example, /tokyo/ works, but /TOkyo/ results in a 404 error, or category 'Abcdefg' would show correctly at mydomain.com/abcdefg/, but mydomain.com/ABCDEFG/ will either 404 or navigate to a different page (that has 'Abcdefg' in the title).
To Reproduce
Step-by-step reproduction instructions
Expected results
Actual results
Screenshots, screen recording, code snippet
If possible, please provide a screenshot, a screen recording, or a code snippet which demonstrates the bug.![image](https://github.com/Yoast/wordpress-seo/assets/39304291/e2279465-5f61-4f34-a5ac-f0429e0f08f0)
Technical info
Used versions