If you put a title that starts with a number and that number coincides with a different topic ID. Then sharing or clicking on a direct link (without the post ID) automatically redirects you to the clashing topic.
For example this post title starts with 101646 which is the POST ID of another topic (this one)
But then if I post a link to this
Copy paste works best for this example
Which is the URL of this (current) topic it redirects to the Topic List Preview (unless I provide the /153975) at the end.
However any other post I can l link to directly as long as they don’t have a shared ID at the beginning of the URL