trouble connecting Eufy homebase s380- S33

Hi! 

First of, I am no techie, but I can follow instructions.  Senior female here who has always hooked up all electronics.  

I hooked up the S33 two weeks ago because we are paying Comcast for 1.2g internet speed and couldn't even stream a movie anymore (directv) that had already started.  I also upgraded to the Nest Wifi Pro system.

Since Comcast often shuts off "for servicing" without warning my Nest security system also shuts off.  We do not have the kind of neighbors where this is a good idea.  To have a backup system I bought the Eufy s380 homebase with two s330 cameras.  Problem is, the homebase will not connect to the Arris no matter which port I use.  The potential issues are "is DHCP enabled?"  and the other jazz such as "is the ethernet cable securely connected?  Is the power cable connected?"

I wonder about DHCP.  But the Surfboard app is useless in that it deals only with setup.  I have no idea where to find DHCP.  It is my understanding that the s33 assigns that automatically.  But the light on the homebase remains a steady red which indicates a problem with connection.   Switching ethernet cables around does not solve the issue either.

I wrangled with Comcast last evening over the still dismal speed.  A tech is supposed to be here between 2-4pm, but the moment he sees it is an Arris he won't touch it but will try instead to sell me on a Comcast rental modem for $15/month.  

I would REALLY appreciate help here.  Is there another app I need to download?  Help, please!