MQTT/keepalive stopped working after upgrade to 3.42

Hello everyone,
I have a problem with the MQTT connection to my cerbo gx.
The cerbo is connected to the VRM portal without a problem and my MQTT-Client is connecting to the VRM portal without problem as well.
The whole setup worked flawless for several month now.
Yesterday, I upgraded the cerbo gx to the new firmware 3.42 and since then the mqtt flow only works if I have an active web connection to the VRM portal (and this installation) open. If I close that connection, the mqtt flow stops after 60 seconds.
Now, I know about the keep alive that needs to be sent periodically and I have configured that with node red on the cerbo. As mentioned, it worked for month’ now. Just not anymore after the upgrade…
Any ideas what I can check for?
Mathias

what version did you upgrade from? Did you check the release notes for what changed in the interim?

Hi,
I upgraded from 3.31 and yes, I’ve checked the release notes and nothing specific in there.
3.32 and 3.33 fixed some stability problems (which I did not have) with MQTT. 3.4 had some traffic improvements and that is it.
Now, back on 3.31 the system works as expected.
Mathias

The flashmq changes were already made in 3.31 but its worth reading the keepalive changes for flashmq if you haven’t already.

Well, I know that too and I configured Node-RED on the Cerbo to be:

Node “TIMESTAMP”: Empty Payload, inject after 0.1 seconds and then every 20 seconds
Node “Keepalive” (input connected to timestamp): Topic “R/XXXXXXXX/keepalive”, QoS 1, Retain “True”.
Server for Node keepalive is “localhost”, port 1883, protocol MQTT V3.1.1
That is the only way to get it to work under 3.31. Now, same config does NOT work with 3.42