I’m having the same issue.
I have the post sort order set to descending and posts per page set to 25.
On multi-page threads (more than 25 posts) the pagination works correctly for most links except the “Last Post” link. When users click on the link under last post column, they are taken to the last page instead of the first page with the newest reply.
Would this plugin resolve this issue?
Or can I edit a PHP file to fix this?