@mhohuh TL-WR940N doesn't support a captive portal. Here's a guide on how to configure portal authentication of some router models (not every model has this feature) - click on the raw down after "...

@Ccooaattssy OK, So what kind of issues exactly you're experiencing - you mentioned something about Xbox NAT type errors - give us some more details on that. Why do you think there is a IP...

@Feelgudd Yes, you could VR900 has three working modes - VDSL/ADSL Modem Router, Wireless Router, 3G/4G Router. In wireless router mode LAN4 is the WAN port, the rest are LAN ports.

@AlifAlHasan If it's possible test with another ethernet cable. If the issue persists it could be a defective unit - you may contact your local tech support for further troubleshooting.

@Ccooaattssy It would be helpful to give more details about the TP-Link products you bought and the network topology you use to connect your Xbox. Usually the device model is printed on the bottom...

@PasBoh Have you tried to disable the TL-WA850RE DHCP server so the only DHCP server in your network be the TL-WR840N's. Reboot the TL-WR840N, after that reboot TL-WA850RE and test if there's an...