Redirect Article- possible?

I’m hijacking the thread because I want to do the exact same thing. Also I’m sure knebb will not get angry as I follow up his original plan (in the same company)

So from my understanding the permalinks should do the redirection from

https://help.domain.com/t/old-thread-title/6418
to
https://help.domain.com/t/new-thread-title/11345

but it does not. I want to transfer the browser call of the first URL to the second one. No internal links direct access to the article.
Like knebb I’m a little bit confused, that this simple redirection is not asked often and apparently not possible.

Thanks for any hint to solve this task. DirkS