This feature is one of the optimisations created to make the heating system truly smart; this function is only integrated on Smart Valve and WiFi electric radiators.
When the device detects a sudden drop in temperature (at least 1.5°C within 10 minutes), it sends a command to switch off the radiator for 30 minutes (regardless of whether the radiator is heating or not at that time).
In the case of a Smart Valve, this will close the radiator.