See a few posts earlier. Going to the URL of an ended listing auto-forwards to a "similar" (using the term very loosely) active listing instead of the one you requested. It's a new "feature."
Apparently, it wasn't good enough that they spammed you with two rows of current listing thumbnails at the top of an ended listing page. Now, they instead force you to look at an active listing page instead. If you really want to see that old listing, you have to click another link, if you happen to see it.
You know your auction platform's sales are bad when you have to resort to tricking your buyers into looking at your inventory.