Two-way communication?

[stuartlangridge]

I've deployed my own back end, and am using the demo to chat between two clients (in separate browsers). Call them client A and client B. I can successfully register identities for A and B, and A can search for B by number and find them, and B can search for A by number and find them, and the "other" party is notified of the new session correctly. However, chat messages only seem to go "one way": if A searches for B by number and then creates a session, messages sent from A to B in that session arrive fine, but messages sent from B to A do not arrive; B gets an error message like No record for device identityB when sending a message. Is this what's supposed to happen? (That is: if I want A and B to chat, am I meant to create two sessions, an A-to-B session and a B-to-A session?) If not, is something happening to incorrectly register the "second" party in the session?