Hard to find an answer here.
If the data (value) does not appear at all, it sounds that the item has no value.
In your first post you had the value “10.302848392”.
Now you have nothing?
I think the best way to come to a solution here, is to try it step by step.
- define a new simple item
- assign an integer to the item
- show the value in OpenHab
- format the value
- change the value
You can add a slider in openhab to change the value directly in the GUI
I dont think it has something to do with the definition of the item but here’s my Item definition:
Number GroundFloor_MasterBathroom_Temperature "Badezimmer [%.1f °C]" <temperature> (GroundFloor_MasterBathroom, HomeTemperature, HomeTemperatureMAX)