New Upgrade Modem/Gateway Installation

In order to avoid any devices in my home to be manually reconfigured, I would like to pre-configure the new modem for the the same SSID, DHCP, Gateway address, etc.
I have it plugged in, see the new SSID, enter the password, and am able to change all that, rebooted both the modem/gateway and my device. Attempt to connect to either the old address, or the new - not functioning. I can give my device an Manual IP address and able to connect again to the admin website, but it is ignoring any changes that I make.  If this is not possible, I would rather keep what I have.

Suggestions?