Sonoff basic shows warn messages in the log for "No publish flow registered ... Hass state?

Pi4b, 2.5.12, sonoff basic with Tasmota 9.3.1

Another topic I do have for a few basics configured in homeassistant mode. I am getting in the log
these messages (see below). The devices do work flawlessly but I am wondering what it is and why only for a few of the same devices with the same setup?

2021-05-04 21:22:00.073 [WARN ] [.incoming.MqttIncomingPublishService] - No publish flow registered for MqttStatefulPublish{stateless=MqttPublish{topic=tele/E-SonneKlein21/HASS_STATE, payload=334byte, qos=AT_MOST_ONCE, retain=false}, packetIdentifier=-1, dup=false, topicAlias=0, subscriptionIdentifiers=[]}.

This is a WARN message from the MQTT Action, which is a version 1 bundle.
Config you need that bundle.
In the message the referenced topic (tele/E-SonneKlein21/HASS_STATE) is stated. You should be able to tell for which MQTT device this message needs to be sent and in which event you do.
Does this work ( it is a WARN, not an error!)

BTW: You published the same question in Dec’20, this message doesn’t seem to bother you after all.

Don’t understand exactly what you mean.
This is just a stupid switch. The device is used in a rule for switching some lights.
I do use multiple Sonoff basics and there are only two devices sending such messages.
Yes it is only a warning and all is working, nevertheless I am interested to understand what causes these warnings.

ATM I’m not sure where this message is really coming from. It looked to me as if it is from the (old) mqtt version, but I can’t find it in the code (MqttIncomingPublishService should be the name of a code file).
What version of mqtt are you using?

The mqtt binding is on 2.5.12, but as you realized I do have that message already for a while.
The strange thing in December last year it was only one sonoff basic, now the second one is stating the same warning. Since December I wasn´t changing the config at all.

I’m sorry, but I can’t locate the source of this warn message. ATM I think it is from the actual MQTT binding ( actual as in MQTT 2).
So no help from my side