Disable Xfinity Flex Wifi

This is not a major issue, but an annoyance. Activated a Flex box and used wifi for a few days before running ethernet. It now defaults to ethernet as is should, however, the box still connects to my modem via Wifi even though it is not using it for data. I've tested it and when I power it back up two MAC addresses w/ different IPs get added, one a number above what is printed on the bottom of the Flex for wifi and one below for ethernet. My Flex box network settings says using ethernet connectivity but you can still see the wifi saved in there with no way to turn it off/disable.  Seems like not a big deal but there should be no reason for my modem/router to process an additional MAC/IP for years to come when I'm not using it. I could click the x in the modem web tool to block from my router but then I'm afraid if I need to enable in the future it will be a pain. I would even take a factor reset of the box to wipe all network settings but that also doesn't seem possible.