@swcunn 

When the drop happens do you notice the LED lights of any of the Deco units changing or turning red?

Here is a reference to the LED status:

Flashing Yellow, Resetting

Solid Yellow, Starting up

Flashing Blue, Ready for configuration

Solid Blue, Ready for being configured

Solid White, Working normally

Flashing White, Upgrading

Solid Red, No access to the Internet

Flashing Red, Lost connection with main Deco

Flashing Blue Rapidly, WPS pairing

@Tony  No, the lights on all of the deco's stay white. Not all devices are knocked off lilne, just some. And not all at the same time. Also noticed that any device that is hard wired via ethernet stays online. 

@swcunn I have experienced the same issues - sometimes the light stays white and other times it flashes red - the slave unit was 5 feet from the main unit because i was testing it. the main unit was getting 350mbits/s and the slave only 20??? i move the main unit around the house (i live in a three story townhouse) and the only way i can get it to stay stable is to ethernet link all the units together and if thats not bad enough i had to buy a powerline to connect 2 of them (isnt that a built in function of the D9 i hear you say - Correct but thats junk cuz it doesnt)

basically these D9 units are complete junk, the wifi range on them is super short and dont make if though normal walls and then the powerline doesnt seem to work and you have no way of knowing how the units are connecting. You also can not change it to 2.4 or 5 ghz wifi so again you get the speed it gives rather than being able to dial it in yourself.

very disapointed as i use TP-Link product all over my smart home and i expected more. My system is working but only because the units are ethernet linked which isnt how i wanted to set these up

@swcunn 

You can try swapping the Deco units and designate a new Deco unit, another thing to try is to see if the connection reliabity is to disable fast roaming and beamforming.

@Tony tried all of those lol. I thought it was just me but I can see that connecting via ethernet showed it to be how the deco talk to each other 

@Tony I don't see an option to disable beamforming in my app. How is this done? Also when I enabled fast roaming it seemed to disconnect less.