[Geschlossen] Why a translad post is not available unless its URL is different from the original

Background of the issue:
I am trying to translate a post to a different language by uploading an XLIFF file, using the Classic Translation Editor instead of the Advanced Translation Editor. The issue can be seen on this page: versteckter Link. I need to work with XLIFF files, so I can't use the ATE.

Symptoms:
The translated post is not available unless its URL is different from the original. I expected to see the translated page, but instead, I got the original page: versteckter Link. Changing the URL makes the page available. This issue was previously solved for the ATE (v2), but it seems unresolved for the CTE.
Screencast: versteckter Link

Questions:
Why is the translated post not available unless its URL is different from the original?
I already faced this issue with the ATE v2 couple of month ago, which you guys solved.
I'd be happy to provide you with the related ticket. Unfortunately, I can't find this ticket anymore (no list of my previous tickets?)
Obviously, it's not solved for the Classic Translation Editor