@Elemental To confirm your suspicions you could use an apps like Wi-Fi Analyzer or inSSIDer and scan both bands (2.4GHz & 5GHz) for a wireless signal still emitting from the router while its wireless...

There's no need to set VR400 in 'wireless router mode', unless you're planning to use it like a wireless router. In this mode LAN4 port is used like a WAN port. In 'DSL modem router mode' you'll have...

@Draco123 Network Map is your best bet: If you used the TL-WA855RE in AP mode there's a chance that on your main router you made a 'DHCP Address Reservation' or 'IP & MAC Binding' for the PS4,...

@thecussen Here's a quick guide on how to do that.

@popkrab Here's a detailed guide on the subject.

@KRIS537 In the second scenario (when AX23 is in 'Wireless router mode') you're actually using AX23's DHCP server. In this case the problem is that you most probably can't turn off your Sky hub NAT...