After some testing, I've found the problem was a wired device that was bringing down my wired network. It was a USB-C dongle, when it was detached from the computer it killed the wired network...

To whom it may concern, I bought a couple of Deco M4 some moths ago, and they worked fine for some time. But recently, the secondary Deco loses it connection to the main Deco: it starts blinking a...