Mqtt discovery sensor

Hi all ,
Supervisor 2023.06.1 Operating System 10.2
I’m trying to create a sensor with mqtt discovery ,I’m getting this error:
WARNING (MainThread) [homeassistant.components.mqtt.discovery] Unable to parse JSON DB1706: 'homeassistant/sensor/DB1706/config, {"deviceclass":"temperature","name":"DB1706","uniq_id":"DB1706","val_tpl":"{{value_json['temperature'] }}","unit_of_meas":"°C","ic":"mdi:thermometer","qos":"0","retain":"true","stat_t":"homeassistant/sensor/DB1706/state","json_attr_t":"homeassistant/sensor/DB1706/state"}'
the error above is reported in the ha logs, the line does not appear on mosquitto when subscribing to the topic.
Publishing these data with the mqtt client in the ha browser ( in mqtt integration) and listening to the same topic I can see the payload received in the subscribe part. But it never reach the mqtt server ( the entity is not created).
Does someone could help? I cannot see any error here…
thank you in advance !

What is the MQTT device publishing the discovery?

It looks like Tasmota Discovery JSON implying JSON, so the standard “upgrade to the latest version” advice applies.

A few tips on Tasmota and a MQTT checklist might also help:

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