I Know this is old (but probably not by BuddyPress standards!) but this is actually an API issue: the WP heartbeat API has to be switched on for the frontend.
My host is Sitegrounnd and they dish out their own optimising plugin which has been responsible for a couple of things not working actually, this is one of them.
Under the environment tab is the heartbeat setting. It was switched off by default for the frontend for site performance reasons.
I Know this is old (but probably not by BuddyPress standards!) but @Heather – brilliant this is it! My host is Sitegrounnd and they dish out their own optimising plugin which has been responsible for a couple of things not working actually, this is one of them. Under the environment tab is the heartbeat setting! funnily enough though I had it turn it on!
