Will the ITC-608T not work with in-line fans or humidifiers with on/off switch?

Inkbird support says My fan and humidifier wont work with the ITC-608T because they have on and off switches. I cannot get a power reading on work one or two when they are supposed to be supplying power. Any imput?

The ITC-608T is an on/off controller. If the fan or humidifier needs to be manually turned on after powering up, it is not compatible with the ITC-608T.
If you want to determine if a fan or humidifier is compatible, please plug it directly into a power outlet, will it power on directly? Does it need to be turned on manually by pressing a button?
If it can switch on directly, maybe we need to check if the ITC-608T is set up correctly.