The Drax Cave/TV story numbers randomly edited

From Tardis Wiki, the free Doctor Who reference

Sometimes when I edit a TV story page, the story number for that page is automatically edited as well, being usually decreased by 1. When in preview mode the story number displayed is still the correct, unedited one. I noticed that often other users' edits also contains story number changes, but I not sure if they experienced the same issue or if they actually wanted to edit the story number.