Virtual Device: set temperature to virtual sensor doesn't seem to work

I have an old device with no smart capabilities, but I placed a temperature sensor in it and I created a flow to determine when it’s on or off (as a simple on/off virtual device).

I created an other virtual device (of a type that has on/off and a temperature sensor; the water kettle). The flow where the on/off is determined also turns on or off this virtual device. This works perfectly.

I also created a flow where, if the temperature of the real sensor changes, it will be written to the virtual sensor. But that one doesn’t work. It says - °C (< it sees it does recognise that it is a temperature!).
When testing the flow with a temperature it says ‘invalid capability’. So it seems it doesn’t recognise it?

I used the ‘set value of virtual sensor’ and double checked if I set the right tags in it. For sensor, it’s the ‘temperature’ sensor of the virtual device and for value, it’s the temperature value of the real temperature sensor.

Am I doing something wrong, or should I use a different virtual device to fix this? I cannot seem to find what is happening.

Please share your flow. Also, assuming that you’re using a tag/token for the temperature value, have you tried using a hardcoded value instead?

and make sure the “input” temperature gets rounded by .5 on beforehand

Don’t use the tag temperature from the virtualdevice, but type measure_temperature