Comcast Compatibility - CAX30

I have a new CAX30 Cable Modem/Router that I have had for less than a month that I purchased to replace an equivalent Comcast product that I was renting.  Everything in my network works fine except I have had some compatibility issues with Comcast.  The configuration I have is (1) master cable TV box and (2) satellite cable TV boxes that connect to the master cable TV box via Wifi.  The problem I have is that the two satellite cable boxes have difficulty connecting to the master cable box via Wifi.  Once a connection has been established, it works fine but every day or so when I power up one of the satellite cable boxes, it doesn't connect to the master, the TV screen is blank, and I have to restart the satellite cable box to get it to reconnect to the master cable box in order to view cable television.

I think one part of this problem is a DHCP issue.   I think the cable box occasionally loses its IP address and has to get a new IP address from the CAX30 router.  When this happens, I suspect that the satellite cable box has difficulty communicating to the master cable box on the new IP address.  To resolve this problem, I assigned both satellite cable boxes to a reserved IP address in the router and that seems to have had a big impact on solving this problem

I am wondering if there are any other configuration instructions on what else might be needed to get the CAX30 to work with Comcast.  The product is advertised as compatible with Comcast, but I can't find any documentation anywhere on what might be necessary to configure it for Comcast.

Thanks,