If you have two routers in series you’ll end up with issues as both will being trying to be the router. You’ll likely have two firewalls and a double NAT. The way to resolve that is to turn off the router functions on one of the routers. You either do one of these two things to make it work.
- Put the modem/router in bridge mode. That disables everything but the modem part of it.
- Put the new WiFi router in AP mode (Access Point). That tells it there is a router upstream and basically disables everything but the WiFi.
If you don’t see the bridge mode option do a Google search on the model number and “bridge mode”. If it is possible that should come up with the steps.
Found it, Page 11 and 72. they call it router mode. You set it to No to turn off the router functions.