Mini boxes on ethernet connectivity issues

[Lovelyday]

Set up:

Sky Q connected by Ethernet

Broadband Airband 

Two Sky Minis connected to LAN port of Nokia Beacons 

Main router Nokia Beacon 

Issue

Minis losing connection to main box intermittently but at least 5 times per day. Sometimes it's enough to turn minis off then on to re establish connection sometimes a reset of Mini needed. Blue screen. 
What I have tried 

Reset all network connections on all 3 Sky Q boxes (main and 2 minis) then turned WiFi off each time (

WiFi on all Sky Q boxes turned off 

power saving off on all Sky boxes 

Rebooted router while Sky Q disconnected and then brought each Sky box up individually. 

QUESTION 

why are the Minis losing connection with main box when network resets should have eliminated need for WPS and minis and main box are Ethernet connected? 

no RFI type items nearby though all Sky products connected to Sonos. 

[oldfella]

Hi @Lovelyday 

Ideally you need all Q boxes connected by the same method and also identical devices.

The minis are connected to Nokia beacons and I assume your main Q box is connected to the Nokia router.

Is the Nokia router an identical device to the beacons?

Or are the Mini connected beacons just satellite devices and not identical to the router?

[Lovelyday]

Yes . All Nokia beacon 2s. The Beacon 2 for the main Q box is the router via an unmanaged Ethernet switch.  . The 2 minis to 2 beacon 2s I run as WiFi extenders minis connected to the mini LAN. 

What is strange is that when the minis disconnect the remote on the mini stops working as in won't turn mini on or off unless I reset. Have changed batteries, reset remotes etc etc.