I have always read my forums by clicking New Posts. I have not seen a single PRSI thread included since the update, yet if I go directly to PRSI, there are plenty of new posts. Is this by design, or accident?
If you scroll up to the top of the page where it says New Posts.... to the far right of that you should see a >. Tap that repeatedly and all the options will scroll by until you get to Mark Forums Read.Maybe I’m missing it, but there doesn’t even seem to be a way to make posts read on the iPhone view.
I've not checked "new posts" but I seem to be getting notifications of replies or reactions to my posts. Not implying you are mistaken though.