There is an issue with the forums that as soon as I open any topic, it starts showing the number of unread posts in it, despite it’s a feature of the tracking level.
I untrack a lot of topics by setting them back to normal. I’m fine seeing them, no need to mute. But, both these and those I just accidentally click on still show up as priority topics at the bottom and show the little blue counter in global lists.
Should be really easy to test. Click on topic with many posts without a counter, press Back, see the counter.
Example: clicking on this topic and pressing back did set me to this state, see post id in link.