ac2300 can't connect to RCN

Hi all

just bought an ac2300 and hooked it up to a working Rcn connection via a Arris sb8200. So the wiring WITHOUT the ac2300 is this machine ethernet cable into port 1 on the modem. It works like a champ.

BUT when I hook up the ac2300 and use the genie to detect the modem it doesn't connect to the internet.

I have hooked the yellow cable from the netgear box into the yellow port on the back of the router and then into port 1 of the modem.  The genie goes off and does it's thing and comes back with the power cycle the modem/ check the cables etc. I check the cable it's fine, I power cycle the modem and wait 5 minutes just to be sure and NO LUCK!!!

I know the modem and the cables are all working because I'm using the direct hook up to the modem with the yellow cable right now to type this message. What am I missing please?

thank you