Hello @JaylanPHNX 

Do you mean you are configuring the same SSID and password settings on the AX73 to be the same as on the old router? If that is the case, was there any error message on the device like unable to connect when trying to connect to the wireless network of the AX73?

Is there a reason why you need to keep the same settings on the AX73? what if you remove the old profile on the devices first, then reconnect to the new SSID, will they connect? Below is the guide to remove a profile on a Windows 10 computer:

How to connect to wireless networks and remove its profile on windows 10?

  @JaylanPHNX 

This is a bit out of my wheelhouse, but you may be able to save the network setup by making sure that the IP ranges, DNS settings, and subnets are the same between your previous connection from the modem to your previous router, as they are to the router that you just replaced. I know that when first connecting to a network, the router will try to take an IP from the modem that has not been used before and has no conflict.

When I changed my last router, my entire structure of IPs changed, and I was able to tell by what IP you connect to in order to access the WebUI, at least I think. The devices may not also automatically reconnect to the router if your new router is using a different security protocol.

Someone else, please feel free to join in and correct me if I am mistaken.

@JaylanPHNX 

 Great. There are cases where we may miss those tiny differences and it could be hard to find out, While you did, great job.