My BuddyPress is located on a subsite and it suddenly stopped taking the activity feed from the network. I don't know why. I disabled the plugins, disabled the network plugins, and it still didn't work.
I moved the BP reference point over to the main site again and it worked, but that's not what I want. So I shifted it back to the subsite (through assigning the BP_blog in the wp-config file) to see if it reset, which it didn't.