@David-TP the network works just fine 

I have an fritz box router where I turned off the wifi 

On my phone I have set an private DNS server

From nextdns 

What do you mean with access control on my router?

  @David-TP 

The Fritz Box is pretty stock besides some open ports UDP/TCP

So no blocking websites 

I will try access point mode thx

Hi  @David-TP, 

So today as I woke up the Deco at the top floor(not the main) flashed red ->Internet still worked 

The bottom one which is the main unit was white so everything good 

Unfortunately I had no time to change to access point mode but I saw this with red light today 

Can i paste in the logs from the decos in here? Would that help?

  @SamsungHandy and @David-TP
Can I ask if this was resolved in any fashion?
Mine is already setup in AP Mode.
Main unit is solid RED.
2 x slave units have flashing RED.
Also can I ask where you got the logs from the unit(s)?

Extra information:-
DNS is configured from router with 1.1.1.1 and 9.9.9.9.
Units are all connected to router via ethernet.
Access seems to be fine, but RED LED's persist

  @Struthm8 

Hi this was kinda resolved yes I have just set the LED to stay on 1min a day so it doesn't have a chance to blink red.

I don't know if that's the solution but it worked for me.

The logs I got from the Web Interface of the decos

Under Advanced->System->System Logs

Maybe try and open this iP in your browser it's the gateway for my decos

192.168.68.1

Maybe it's your DNS Settings try setting them in the Deco app 

  @SamsungHandy
Thanks for the feedback.
I have managed to browse into the units and see the logs.
I do see this entry 22 DEBUG 0days, 00:00:21, [smarthome]tlcc_get_link_status:1! [1-disconnected 2-connected 4-reconnecting]
I think that means 1-disconnected but the internet connection through all units on all devices seems OK.
Same trick with setting LED's to be OFF most of time seems to work for me, but I think this is just masking the issue.
These are brand new units.