@David-TP 

Hello! I'm too having the same issue with my deco network.

Model: Deco M5 AC1300 ver. 3.0

Firmware Version: 1.7.8 Build 20240719 Rel. 70981

I have 5 Deco devices connect via Ethernet cable with about 41 clients across the network.

Every device shows as connected with Ethernet, but constantly and repeatedly one device keeps showing as offline and then online (showing 0 clients) even though the deco is always with the green light turned on. 

I've always used my deco network in Router Mode, with the main deco connected to a internet provider modem that was set to router mode too, creating a subnet inside my network. Ive changed this setup, setting the internet provider router to bridge mode, so only the Deco network is being used as the router, uniting the whole network. The Deco now resolves the internet connection from the router using a PPPoE authentication method. Starting the day I made this change, I have constant problems with the Deco app reporting wrong data like Decos appearing offline but they aren't (green light), and a network map showing only 3 decos.

The only thing to note is that the main deco called M5 is connected to the other decos through a network switch. This was always the case and never caused any problems. Now using the decos as the main router (receiving the internet from the network provider modem) the network map is showing different data all the time. Any help is appreciated. Thanks!

  @David-TP 

Thanks for the reply! I wasn't aware of the new 1.9.0 version as apparently it wasn't released in my region. The app also does not show any new updates.

You see: I am located in Brazil, and in the local Tp-Link website, the latest available version is 1.7.8 and is labeled as a US device version. Changing the TP-Link website to the US version also only shows the 1.7.8 version. The link you provided apparently shows the EU version that is 1.9.0.

Is it OK to use the version you provided?

Also, the Switch I'm using is a LiteWave LS1008G Gigabit 8 Port.