Unread Topics doesn't seem to work consistently

[#1]

Normally clicking on unread topics shows all the topics where there has been a new post not just totally new topics

However I just had an odd thing happen

I had a popup advising that Chris had posted in a topic I was following  so - rather than going to my notifications I clicked on Unread Topics and it wasn't there. I clicked on Unread Posts and it was shown

[#2]

I wonder if it's simply down to a delay with the lists updating and/or the "page" needing a refresh? I was watching just now after I had a pop-up of a reply and when I first checked Unread Topics it wasn't there, but it was on Unread posts. When I check back a short while later it was - I may have done a refresh - wasn't paying that close enough attention But this isn't the first time that I've noticed delays between various things like pop-ups, Notification feeds, thread lists etc.