MoCA filter installed on my gateway device, but my neighbor is still connecting devices to my network

Came back from a work trip to find that a bunch of devices had been connecting/accessing my network while I was gone via ethernet. I am also assuming my neighbor has a router plugged in via ethernet to service wireless devices on what is supposed to be his network. MoCA filter has been installed since the initial setup of my router/modem. I live in an apartment building so I knew this was a security issue.

Despite having a MoCA filter installed, my router/modem's interface tells me that I don't have any MoCA devices connected, and therefore doesn't enable the MoCA security setting listed in the top right corner of the interface (shows as MoCA with an red "X" next to it). If I navigate tot the MoCA tab under the Connection drop-down on the left side of the interface, MoCA is listed as enabled. The MoCA Diagnostics interface under the Troubleshooting dropdown states "Currently MoCA devices are not connected to the Gateway" and the Privacy function is stuck on "Disabled."

No direct way to contact xfinity support about this so here I am. Can someone please tell me what I am doing wrong? Happy to provide more information as needed.