I posted the question below in the “Forum Updates / Issues” subforum but no response. It has been a month of waiting and I make an attempt here before giving up but my hopes are not high:

Am I the only one who can’t find that button (if it exists)? There are topics of interest to me and others that are not. I don’t want to open every topic just to kill the new posts notification. Anyone with any comment would be appriciated but most of all, a “mark forum or all forums as read” button!

Now, please, do something about it!