Azure IoT Central, raw data empty after name edit

Question

I am currently trying to get into Azure IoT and following the tutorials I was able to connect a temperature sensor on my raspberry with IoT central.
Whenever I receive some raw data it gets displayed in IoT Central as:

{
"thermostat1": {
"temperature": 25.75
},
"_eventtype": "Telemetrie",
"_timestamp": "2021-09-08T12:19:00.138Z"
}

Now I wanted to expand a bit by adding more input data sources by using a different sensor, but as soon as I edit the name of the input in the model the raw data dict changes to:

{
"_eventtype": "Telemetrie",
"_timestamp": "2021-09-08T13:17:34.827Z"
}

That is, the values are gone.
I have tried to provoke some errors by either only changing the name in IoT central OR my sensor script.
In that case the dict looks like this:

{
"_unmodeleddata": {
"thermostat1": {
"__t": "c",
"temperatur": 25.562
}
},
"_eventtype": "Telemetrie",
"_timestamp": "2021-09-08T12:37:26.056Z"
}

With the scripts key value being "temperatur".

So it seems like the values do get received by IoT Central, but as soon as the key name matches for both IoT Central and is not the original name (temperature) it seems to disappear.

Does anyone happen to know how to fix this?
Did I perhaps forget to change another setting?