This unit reported malfuncted. Deleted then cleared then re added. It will only add as “other device” and not thermostat.
It’s on an IQ4
Is it being paired while within 6 feet of the panel?
The CT100 uses an old Z-wave radio version with more limited range and is no longer officially supported by ADC on accounts created after 2018.
If pairing within 6 feet proximity does not resolve the issue it is possible the CT100 radio is at fault.