I think you may have asked about this before, and at the time I seemed to have something similar going on, but I couldn't quite put my finger on it.
I think it's the same as you though: I'm not quite sure what triggers the board software to "know" I'm in a new session. I think the problem may be that I don't sign in and out but stay signed in??
At any rate, if I come back several times in a day (and who doesn't

), and I click "new posts" at the top of the board to get a list of new threads/posts, and then click on the "go to first new post" chevron at the beginning of a thread, if it's a thread that I have read earlier in the day, it will always take me back to that earlier new post and not the newest new post. Sometimes these are not even on the same page if it is an active thread.
What I'm not sure about is where is the cut off, because *sometimes* when I come back, it does take me to the "real" first new post. So, like you, I'm wondering what is telling the board that it's a new session, and is there a way for me to trigger that?
Not a huge issue, but probably like you, I'm wondering if it is just some silly little thing I'm doing or not doing that I could change.
Blue Sparkle