@bj0 See the reactive coroutine guide, conflated keeps the latest message and resends it to every new access of the channel whereas the array version only sends to those listening to the channel while values are being sent, it looks like all the values were sent before the other async started (or the delay makes the receive miss the send? Did you try receiving without any delay or a longer one on the receiving side?)... Also, why do you use openSubscription, I think that is only for subscribing to a reactive publisher, on a channel you can do for in directly on the channel...