And this is the log of the MQTT Client app on Homey:
20201129-10:36:00 SendMessageToTopic called
20201129-10:36:00 SendMessageToTopic: {"qos":0,"retain":"1","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power","mqttMessage":0.89}
20201129-10:36:00 publish_options: {"qos":0,"retain":true}
20201129-10:36:00 send 0.89 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power
20201129-10:36:01 SendMessageToTopic called
20201129-10:36:01 SendMessageToTopic: {"qos":0,"retain":"1","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power","mqttMessage":0}
20201129-10:36:01 publish_options: {"qos":0,"retain":true}
20201129-10:36:01 send 0 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power
20201129-10:36:01 SendMessageToTopic called
20201129-10:36:01 SendMessageToTopic: {"qos":0,"retain":"1","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/current-weather/measure-temperature","mqttMessage":0.22}
20201129-10:36:01 publish_options: {"qos":0,"retain":true}
20201129-10:36:01 send 0.22 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/current-weather/measure-temperature
20201129-10:36:01 SendMessageToTopic called
20201129-10:36:01 SendMessageToTopic: {"qos":0,"retain":"1","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/current-weather/measure-gust-strength","mqttMessage":27.65}
20201129-10:36:01 publish_options: {"qos":0,"retain":true}
20201129-10:36:01 send 27.65 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/current-weather/measure-gust-strength
20201129-10:36:01 SendMessageToTopic called
20201129-10:36:01 SendMessageToTopic: {"qos":0,"retain":"1","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/current-weather/measure-apparent-temperature-capability","mqttMessage":-3.91}
20201129-10:36:01 publish_options: {"qos":0,"retain":true}
20201129-10:36:01 send -3.91 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/current-weather/measure-apparent-temperature-capability
20201129-10:36:05 SendMessageToTopic called
20201129-10:36:05 SendMessageToTopic: {"qos":0,"retain":"1","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power","mqttMessage":0.56}
20201129-10:36:05 publish_options: {"qos":0,"retain":true}
20201129-10:36:05 send 0.56 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power
20201129-10:36:06 SendMessageToTopic called
20201129-10:36:06 SendMessageToTopic: {"qos":0,"retain":"1","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power","mqttMessage":0}
20201129-10:36:06 publish_options: {"qos":0,"retain":true}
20201129-10:36:06 send 0 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power
20201129-10:36:08 SendMessageToTopic called
20201129-10:36:08 SendMessageToTopic: {"qos":0,"retain":"1","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power","mqttMessage":0.9}
20201129-10:36:08 publish_options: {"qos":0,"retain":true}
20201129-10:36:08 send 0.9 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power
20201129-10:36:09 SendMessageToTopic called
20201129-10:36:09 SendMessageToTopic: {"qos":0,"retain":"1","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power","mqttMessage":0}
20201129-10:36:09 publish_options: {"qos":0,"retain":true}
20201129-10:36:09 send 0 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power
20201129-10:36:15 SendMessageToTopic called
20201129-10:36:15 SendMessageToTopic: {"qos":0,"retain":"1","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power","mqttMessage":0.71}
20201129-10:36:15 publish_options: {"qos":0,"retain":true}
20201129-10:36:15 send 0.71 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power
20201129-10:36:16 SendMessageToTopic called
20201129-10:36:16 SendMessageToTopic: {"qos":0,"retain":"1","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power","mqttMessage":0}
20201129-10:36:16 publish_options: {"qos":0,"retain":true}
20201129-10:36:16 send 0 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/droger/measure-power
20201129-10:36:26 getLogLines called
20201129-10:36:41 SendMessageToTopic called
20201129-10:36:41 SendMessageToTopic: {"qos":0,"retain":"0","mqttTopic":"homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/$stats/uptime","mqttMessage":"3722"}
20201129-10:36:41 publish_options: {"qos":0,"retain":false}
20201129-10:36:41 send 3722 on topic homie/homey-xxxxxxxxxxxxxxxxxxxxxxxx/$stats/uptime
20201129-10:36:47 getLogLines called
I also tried the test version of MQTT Hub