@Jindrich I think you meant Deco M5 mesh (not D5). You can have all Deco units, Main and Satellites, connected through LAN. Also, for maximum flexibility on how you can hardwire Deco units, Deco mesh...

@TJV1979 According to TP-Link, the Deco's IoT network does not automatically isolate devices from the main network. Which means, if you need to manage your IoT devices from smartphone, that...

@Boriy The problem is most likely Ethernet cable between two Deco units that talk to each other over WiFi. You should replace it.

@BhairavP Pulsing blue light on M9 means it is ready for setup. Which means it has not been properly setup yet. What do the different LED colors meaning of Deco? Power off that M9 Plus. Unplug from...

@Iggy888 I would trust Ookla speed test app in that case. Results are still not good. In Deco Router mode, a lot could impact speeds. If you have preferred/priority device, remove that. If you have...

@Iggy888 For speed testing, install Ookla speed test app, which is available in Windows app store, Apple app store and Google app store.