Ron
It really is random. I've just caught up from about 6 hours ago. Read a few posts with no problem, but then went to the 'First RCR's in the UK post in the RCR forum. Had previously read up to post #23 which was posted on 29th September. Therefore it should have put me in at post #24 posted today, but instead it put in at post #1. And I definitely clicked on the 'go to first new post' tick. I was concentrating really hard on making sure I did it properly, just it case it was me doing something wrong.
I still have the 'problem' where it no longer remembers what is unread in a particular forum, if I do not visit it on a particular visit. So if I am away for a week, and can't catch up in one sitting, then on my next revisit I have to guess.
Sometimes it even times out during the first visit, so if I get involved in reading one forum, by the time I get to the next, all the unread marks have gone. They have not gone on the Forum front page - that still tells me there are unread posts in that forum, but when I enter the forum, there are apparently no unread posts, except I know that there are - somewhere. I have had this later issue with the new forum since it started, which I can live with. It just doesn't feel quite right.
All the best