XER10 not showing up on xfinity app after install

Good evening. i recently installed a XER10 to my fiber internet. I am receiving internet but in my app it show that i am offline. I have been on the phone with service and they still show the CM MAC of the old modem on my account, and when they try to add the Device MAC from the XER10 they are getting an error. I am located in Cologne MN.