BuddyPress.org

Nope. You are not the only one. Strange behavior in messaging. Ya, autocomplete only looks at your friends list. That’s easily fixable. I was having probs sending msgs to valid usernames. No messages sent. No error msg.

https://buddypress.org/forums/topic.php?id=413

I musta posted right after you. Been impatient and cranky lately. Not scanning the forums before I post. Happens when I can’t get a major feature like groups and messaging to work right.