I tried to mute a subforum as I am no longer interested in anything that is going to be posted to it. I have noticed that it does not actually stop the topics posted in or created there showing up in the live feed largely defeating the purpose of muting it at all.
@Thinking_Emoji has since confirmed that muting subforums does not mute the new or updated topics from that sub forum showing up.
I have exaly never had time to actualy test that feuture out. But Moderators cannot realy fix issues according to forum functionalities. Maybe @wendell could take a quick dig trough the forum settings wenn he has some time for it.