This can be somewhat annoying, but... The "recent questions feed" link on the front page gives you a feed of active questions (same as what's displayed on the front page). So every time a question is modified (edited, answered, answer-edited, etc.) it'll reappear in the feed.
If you want to get a feed of new questions only, you can use https://raspberrypi.stackexchange.com/feeds/newest instead.