Not saving my last read post?

In the new user guide it states:

Selecting a topic title will take you to your last read post in the topic.

But I can’t seem to get this to function. Any time I open a post I’ve looked at before I have to manually scroll to the bottom. I see there is a button for going to the bottom but what if I am coming back after a few days and want to resume where I left off? Is it something in preferences I am missing or is it an issue on my end? Using Firefox and ad block is disabled for

This actually happens when you visit a topic that you already read before, it will take you to the first post. In case that there is a new post in the topic you want to see, it will take you to the last unread post.