This may not help but is it really new? And not a so called “refurbished” units?

It was being sold as new (and priced as new) and had factory seals inside and out.

The modems MAC address can be found in the three locations described below;

1) On the white label on the bottom of the box.

2) On the “Product Information” page of the web interface (192.168.100.1).

3) On the “HOME” page of the Surfboard app (if applicable).

Do your MAC addresses all agree and are they the address which Xfinity is trying to provision? If so, then I am stumped.

Yes, all the MAC addresses were the same on the box, the label and on the booklet.

To add, I did not check it in the app because trying to access it in the app, I kept getting an error that I was offline which stuck me as a strange oxymoron that I was using it to get online but I needed to be online to set it up!

I’d contact support. Its going to need to be replaced if the mac address is truly already in use. 

Thank you for your assistance. I’ve already returned it to Amazon.com for a refund. In the meantime, I am wondering if perhaps someone bought it and, leaving it sealed, entered in the MAC address from the end of the box but then returned it without opening. I have no idea why anyone would do that but I can think of no other scenario! It makes no sense having the serial number and MAC address printed on the outside of the packaging but it was indeed there.

We are extremely sorry for the bad experience with HFC MAC ID. Will take your concern on the same to our technical customer support team. 

Thank you and I’ve already returned the modem for a refund as it was useless to me as it was. I’m continuing to use my old one.