Ip address conflict/can't port forward

I am unable to port forward. Whenever i try to open a port I select the device I want and its reserved ipv4 address is different then its actuall ipv4. My laptops ipv4 is 10.0.0.60 but xfinity thinks its address is 10.0.0.61 and the port wont work. Also i dont know if this has something to do with it but it also gave 2 different computers the exact same ipv6 address.