Blinking downstream light no connectivity on 2 different DOCIS 3.0 modems.

Cox preferred 150 internet only account. Was using sb6190 modem when internet went out last week. Called cox to TS the issue was referred to modem manufacturer. Arris was no help so I replaced my modem for new Netgear  cm700 DOCIS 3.0 completely compatible. Connected directly to computer with Ethernet cable to wall with short coaxial cable. No splitters. Connected to power and it does same exact thing my sb6190 did: the power light I’d green and the downstream light is blinking. I called cox thinking the new modem needed to be activated but cox agent tried multiple steps but he was unable to see modem at all. I ask if we could schedule a tech but he warned I may have to pay since this is my equipment. I know cox is doing a lot of updates in the area also based on what I have read the issue is there are no downstream connections being made ... should I schedule a tech?