@Thunderpanths 

Hi, do you mean the client list on Network Map page? Please share with us the screenshot.

Besides, the two client devices with the same IP address are online at the same time or one of them is offline? please note that many wireless client devices now support private address (also called random mac address), so if the private address is enabled on your client device, it will use virtual mac address and change frequently, in that case, maybe the same client device will show twice or more with different mac addresses.