Hi

I purchased and setup 4 x S7 Decos about 6 weeks ago. They all ran perfectly for over a month, but now the "main" keeps losing internet connection (up to a few times per day). Most of the time (if I have the patience) it restores connection within a few minutes (5 - 30), other times a deco reboot fixes it. 

What I have tried so far:
1. As suggested in the app guide, disabled Beamforwarding (Fast Roaming was already off)
2. Changed the DNS from default to 8.8.8.8
3. Double checked that wifi on my router itself is off to prevent it clashing with the mesh network

When those didn't help, I took one of the "slave" devices, moved it to the "main" position, and made it the main in the application (trying to eliminate a faulty device). Didn't seem to help. 

My network details:
4 x S7 all connected via ethernet (Router to main, main to first "slave", slave to slave) beyond that. 
2 x E4 connected wirelessly (at the furthest most points)

Any suggestions on what else I can look at?