Although, like always, I’ve tried searching this topic for around 1 hour, but couldn’t know if this is a noted thing or not (or am I wrong in observing this).
In dark theme, there is very little contrast/difference between ‘read’ and ‘un-read’ topics (when there is no blue dot), particularly on PC. And it is indeed a bit difficult in ‘Suggested Topics’ list as to which topic has been visited/read by the user and which is new.
Since, on meta, even after tying for 20 minutes I couldn’t reach a screen, where some ‘read’ topic would show to me in the ‘Suggested Topics’ list, I’m producing the main/home screen, where 2nd topic has been read by me, 1st and 3rd not.
Succeeded in getting another shot with three topics, 1 fully read, 1 read but with new posts, and 1 unread.
Hope I’m reporting something new.