Home Assistant (VM on Windows PC) with MQTT Broker (in HASS) and ESP8266 (D1 mini) - unknown values

Hi HASS-Users!
I tried several things to send some values (temperature) from ESP8266 to HASS.
I used DS18B20 to check the temperature and publish this information with PubSubClient via Wifi to my HASS which runs as a VM on my Windows PC.
In HASS, I use Mosquitto Broker and I’m able to see the values in the Mosquitto Broker (I can start listening on the topic).
I activated auto detection and I can see in the Mosquitto protocol my ESP8266Client
→ 1642544036: New connection from 192.168.0.201 on port 1883.
{“result”: “ok”, “data”: {}}1642544036: New client connected from 192.168.0.201 as ESP8266Client (p2, c1, k15, u’Chris’).

In parallel, MQTT Explorer runs on Windows to check all published values.

In Configuration Yaml, I also added the sensors in different ways but the result always is that I cannot see any values in the UI/Dashboard e.g. Gauge, etc. → always unknown values.

Any hints from your side?
Of course, I can post all sketches and files I already used or uses.

Thank you and Br, Chris

I already found the issue.