What are you trying to do?
From what I understand, you have one of the ISP provided modem/combo router right from Spectrum and you hooked it up to the Ruckus ICX switch and have the Ruckus R510 APs in a Lennar Home.
You can have the spectrum modem/combo/router to continue handing the routing, but with Wifi turned off and let the Ruckus R510 APs handle the wifi portion. Your spectrum Router will be the DHCP server and hand out all the IPs to your wifi clients though Ruckus APs. There is no reason the change the IPs of your Ruckus APs and have it hand out a different subnet than your spectrum combo router since the spectrum router doesn't handle different VLANs.
Make sure you did the typical setup for the Ruckus APs and not use them in gateway mode. The Ruckus APs will just be APs and no routing is involved while the Spectrum modem/combo router will handle the routing and DHCP address assignments with wifi turned off on the combo routing.