Hi I cannot delete unused device from insight netgear, if i click on device that is online i have delete button but unused\offline device there is no option. The same situation is on Mobile App.
Kindly check the image below. In the Cloud portal, the GC728X switch is an offline device, when I hover to the right of the device, a delete option appears.
If you don't see the same option as shown in the above image, kindly post an image of what you see on your Insight Cloud Portal and Insight App.
