I have a simple flow, Ubuntu server, 2 Pi-4 Clients. Communication via MQTT between clients and server.
On the server I set the MQTT out node to "Retain Message", so when the client would start it would get the last message. It worked. I no longer need this, but even though I unclicked "Retain Messages", then clients are always pulling a message.
Is there some cache I need clear or what have I missed!!!
Thanks in advance.