Which Wi-Fi versions are compatible with the Cook-Key®? The Cook-Key® works with best using a 2G (2.4 GHz connection) instead of a 5G (5 GHz Connection) as it is not compatible. Related articles How does one troubleshoot the Wi-Fi connection when the TM5 has been successfully configured but Cook-Key® cannot connect? How can I update the software on my Thermomix ® TM5? What does error code C561 mean? My TM6™ is showing an error code, what does this mean?