After the initial set up the Deco M5s everything was working well. However at some point the main Deco stopped talking to TP-Link and had a solid red light. The other 2 then had a flashing red light or a solid red light. They are running in AP mode. They did not seem to have a local ip address, the value that they had in the DHCP server was not longer there, and it was not ping able.
Even though this was happening the internet from all PCs and devices that are hard wired to them (via a switch) still had connection to the internet through their internal link.
This went on for weeks, until suddenly the main M5 went green, no reason that I could see, unless it was because I changed my password again. It was then accessible and able to be managed directly and via the app.
I then tried to remove the hard red light on the study M5. Rebooting, and powering it off did not have an affect. Decided that I would have to factory reset it. Pressed the button and it came up with a blue flashing led. Went through the set up process. Seemed to be working. Rebooted itself, and eventually came back with a yellow flashing light. Was wondering it was not working. Looked at the Bedroom M5 and it was now green. Sort of good, not sure what it was connecting to.
Tried again with the study M5. Nothing worked, could not be found, eventually followed the video in one of the trouble shooting guides. Nothing worked, not directly connecting it, not sitting it beside the other one. I did try setting it up as a new network and that worked, but reconfiguring my entire network as a solution is not sensible.
The only thing I can think of is that the network already thinks that this device is part of the it, so will not let it reattach or reconfigure. There is of course no way to actually remove a device from the network.
So currently I am down to 2 of three devices that I bought and if I can not fix this issue I will probably be returning them. They are neither Smart or Reliable.
With the main M5 as soon as it is disconnected from the internet, the red light comes on, and as far as I can tell never goes green again.