Using Beagle IM 5.3.5, I created a public channel on my personal prosody 0.12.4 server

Immediately after creating the channel, my other clients left all of my group chats and channels, and my bookmarks were gone! (the leaving may be because the XEP says to leave the room when its bookmark is deleted https://xmpp.org/extensions/xep-0402.html#notifications)

I inspected the PEP nodes using Gajim, and my bookmarks nodes were indeed empty.