@pukupuku 

Hello, sorry to respond late.

As per your description, it seems that the main Deco is stable but the 1 satellite Deco is dropping, please help confirm the below and we will help fix it:

1. What is the network topology/network diagram? Is the main Deco working as a router? How do you connect these devices together? Please tell us the MAC address of the problematic satellite Deco, how far is it from the others?

2. How often did it drop the connection? And how do you make it back to work? What is the LED status on it? When they disconnect from the network, any notification on the Deco app? Like this Deco is offline? At that time, please connect your computer to it and click here to get the IP and gateway.

Meanwhile, try to exchange the locations between this problematic one and the other satellite unit, then verify whether it is the Deco itself or the network environment which affects the performance.

3. Who is your ISP and what kind of modem are you using?

Any updates, please let me know.