Just an update on this. Seems the problem has been solved. TP-Link (bless them!) logged onto my machine and spent the best part of probably an hour debugging the Deco to diagnose/cure the problem. A...

@Alexandre. It is bizarre, because for month(s) all was fine. And then one day there was my HP Printer on the GUEST list. And it's never left! The fact a wired device obviously cannot even be on the...

@Alexandre. I want all traffic to go through the main Deco (AP mode) so I can see the behaviour of all connected devices. DHCP range of router is 192.168.0.2 to 192.168.0.254. The fact the new...

@Alexandre. The devices in question have been defined as static IP address on my ISP's router for years, without problem... Router's IP is 192.168.0.1. The DHCP range is absolutely fine. Fixed IPs...

@Alexandre. At the moment NO devices are defined to be on the GUEST network. ie: All wireless devices are on the main (WIRELESS_MESH) network. For some reason, initially one, now two, hard wired...

Incase anyone else has been sent a new firmware to test on this matter, I thought I'd give my feedback/update. After applying the firmware update supplied by TP-Link to my M5 Decos, the problem has...