On mobile (I’ve not checked desktop yet), as of today, underneath the last reply to a topic it only lists Related topics which I never use.
It used to have a tab for that and one for Unread topics but that’s gone, something I use all the time to avoid having to go back to the front page to get to the next unread topic.
Any chance we can have Unread back? 
Stand down: this is working normally today, maybe just a glitch 