@gmlupatelli If your Main Deco connected to Router/Gateway (and not just to Modem), there is workaround.

@Pmailley Firmware in your Deco M5 is too old to be upgraded through the app. See this document for other options: How to Update the Firmware of Deco After you managed to upgrade firmware through...

@GCConsulting With Deco X90, the only way to do what you want is by connecting Office Deco to Living Room Deco with Ethernet cable. Using powerline adapters as a substitute to Ethernet cable...

@Ozzo76 You will see the difference if your Internet is faster than 500Mbps and your mobile device connected to X60 supports WiFi6. Also, you must have X60 as your Main Deco.

@Trick753 It would be better to link each Deco M5 with Ethernet cable, if you can. Worth the effort. If you can't, there is still significant benefit of linking just furthest away Satellite M5 to...

@ratelg Review this first: Why is a device displayed as an unknown device on the Deco app？ I am not sure from your problem description if this is relevant document, but just in case. After that, see...