So today I gave Wifi another go, played 4 COD Vanguard Multiplayer games without interruption but then it crashed/lost connection. I immediately checked the PS4 connection in the system menu and that was down, however I checked my laptop at the same time and the speeds were normal with no loss of connection, the laptop was 6ft max away from the PS4. The PS4 wouldn't reconnect until I restarted it.
I've ordered some of the broadband over powerline adapters and they'll come on the next couple of days so it will be interesting to see if the connection is more stable with those. I'm still not sure why the PS4 loses connection when other devices in the same room don't.