TYPO3 Core

IMHO it is still reproducible on 13.2.0-dev (latest main) with the following procedure:

Prerequisites¶

• A TYPO3 installation with
  • a "Home" root page (the one auto-created with the installation for example)
  • a Site Config with the following (minimal) setup:

- Root Page ID [rootPageId] : Home
- Site Identifier [identifier]: main
- Website title [websiteTitle]: TITLE
- Entry Point [base]: https://typo3.main.it.ddev.site:8443

with this config, for example, a subpage "test" will have

- URL: https://typo3.main.it.ddev.site:8443/test/
- TAG <title> : TITLE: test

Test procedure¶

• Create a subpage of "test" called "Test-90163"
• mark it as root [is_siteroot] = 1 (tab Behavior)
• create a subpage "test-90163" of the "test" page

The page has the following characteristics:
- URL: https://typo3.main.it.ddev.site:8443/test/test-90163
- TAG <title> : TITLE: Test-90163

• Go to "sites" module > the new root page "Test-90163" has been detected and TYPO3 offers to create a new config file; create a new config entry with the following (minimal) setup

- Site Identifier [identifier] : test-90163
- Website title [websiteTitle] : MY TITLE IS test-90163
- Entry Point [base]: https://typo3.main.it.ddev.site:8443/mysubsite

now the page has the following characteristics:

- URL: https://typo3.main.it.ddev.site:8443/mysubsite/test/test-90163
- TAG <title> : MY TITLE IS test-90163: Test-90163

• Now Edit again "Test-90163"
• unmark it as root [is_siteroot] = 0 , save it

Results¶

1. on the Sites module the "test-90163" config is no more listed
2. The page can be still reached with the URL: https://typo3.main.it.ddev.site:8443/mysubsite/test/test-90163
3. If I edit the page > Tab General > URL Segment [slug] : the "fixed" part is still https://typo3.main.it.ddev.site:8443/mysubsite
4. TAG <title> : it is still: MY TITLE IS test-90163: Test-90163
5. I have no way to tell that there is a Site config applied to that page AFAICS
6. To undo the config, I deleted it on the filesystem and cleared the cache

I suspect that the same issue applies to TYPO3 12, therefore I raise the version to 12