said by Appy9:however I did plug in an ethernet cable from the laptop to the ATA device to be sure there's connectivity to the ATA device.
That will not work because your ATA is not a gateway, doesn't have 2 LAN ports. If you unplug it from the router will not get any IP address. It's a way to setup static IP addresses on ATA and laptop from the same range but no need to complicate the things. Instead leave the ATA connected into the router and also connect your laptop into the router. Most likely the problem is with the web access not enabled as grand total pointed out and once enabled should work even with the laptop on wifi.