Changing Cox Panoramic System to 3rd Party Mesh System

Help! So I currently have the Cox Panaramic system with one box hard wired in at one tv... the other tv's are the wireless boxes. I pay for the Gigablast internet service but am only getting about 56mpbs when I do the speed test. A few people told me to get a mesh system and so I did. I purchased a Netgear CM1000 modem and eero pro mesh routers. However, when I tried to activate my modem with Cox, they said all of my tv boxes need to be hard wired in... they cannot be wireless. Is this true? The tech was super sweet, but she didn't even know the error I was getting.... so I don't feel too confident with her answer. HELP!?!?! ANYONE??

Do I really need to return all of my wireless tv boxes and get the ones that are hardwired in by a coax cable?