update

src/communication.jl

@@ -535,7 +535,10 @@ end
 #  Signature
 """
 function sendMqttMsg(outgoingMsg::Dict{Symbol, T})::NamedTuple where {T<:Any}
-  mqttMsgReceiveTopic = ["/GeneralUtils_sendMqttMsg/$(outgoingMsg[:msgMeta][:senderId])"]
+
+  # sendMqttMsg() doesn't need to receive msg but mqttClientInstance_v2 requires to have receive topic
+  mqttMsgReceiveTopic = "/GeneralUtils_sendMqttMsg/$(outgoingMsg[:msgMeta][:senderId])"
+
   mqttMsgReceiveChannel = (ch1=Channel(8),)
   keepaliveChannel = Channel(8)
 
@@ -548,7 +551,7 @@ function sendMqttMsg(outgoingMsg::Dict{Symbol, T})::NamedTuple where {T<:Any}
 
   mqttInstance = mqttClientInstance_v2(
     outgoingMsg[:msgMeta][:mqttBrokerAddress],
-    mqttMsgReceiveTopic,
+    [mqttMsgReceiveTopic],
     mqttMsgReceiveChannel,
     keepaliveChannel,
     onMsgCallback;