In my Threads I'm On list, usually clicking on the preview of the most recent post takes me to that post. In several threads lately, it has only taken me to the initial post of the thread, with the entire thread on one page (sometimes hundreds of posts). If I scroll to the end to see the latest post (that there was a preview of in TIO), it is sometimes not there.
Other times it TIO works fine.
I am on a Mac desktop, using Firefox.