Hi, My network is compose by 2/3 Deco P7 and 1/2 Deco M4R. 

The main is a Deco P7- switch 8ports gb- 1° Deco M4R first floor- 2° Deco P7 second floor connected to wifi with the main- and 3° Deco P7 (switch 5 ports gb) in third floor with the ethernet cable.

The problem is on third foor with P7 because during the day it down(with the green led, but it don't have a internet connession) and I have to unplug it to make it work once a day.

Because I have another M4R in the box, I Install It in place of Deco P7 with the problem and It works without the problems. 

Why it works without the problems? 

(The switchs is connet with the deco main, but sometimes the Deco P7 (third floor) connect with the Deco M4R (first floor),

with the configuration of 2 M4R this doesn't happen, all are connected to the main switch(8ports) and deco main)

The P7 devices have benn replaced by amazon since the ones, I had before had the same problem and I thought it was a defect, but these substitutes also do the same.

Thanks.