I see what you mean, Simon. I hadn't noticed this until now. What most likely has happened is that Jive (our communities platform provider) has rolled out some quarterly updates that have affected the community stream. Let me look into it further and get back to you. In the meantime, by my name in the upper right is an orange button with an "@" symbol and the # of items in my Jive inbox I haven't read. If you click on this button, does it provide you with your Connection Stream items? Within your inbox, if you click on an item, it opens it on the lower part of the page and you can respond from there (as I am doing with your post).
Will get back to you with more info.