Unfortunately the forum seems to work like this...
If you read a thread, and scroll to its bottom (as you might when reading its posts one after the other) then navigate away from that thread to another without first scrolling back to its top - you'll land in the new thread at the thread bottom (or at least, not at its top)
To be clear - I'm saying the most recent posting IS on top. But your navigation puts you NOT at the top.
If you are saying something different - please describe.