I’m having some issues with my Satellite Decos disconnecting (Red Blinking) and not being able to reconnect but only when on ethernet.

Routers:

Modem/Router - Huawei EG8245H5

Main - Deco M5 (US) Ver 3.0

Satellite 1 - Deco M4R (US) Ver 2.0

Satellite 2 - Deco M4R (US) Ver 2.0

Switches (Unmanaged):

Switch 1 - TP Link TL-SG105(UN) Ver 6.0

Switch 2 - TP Link TL-SG1008D(UN) Ver 8.20

Etc:

Ethernet coupler

Area:

The area is 2 floors. I placed the Main deco on the upper room close to the modem/router from my ISP. I placed Satellite 1 on the lower room below and then on an adjoining room.

Main Deco and Satellite 1 are close enough for Wifi but I initially connected them via ethernet. Satellite 1 and 2 are too far away for Wifi mesh so I also put Satellite 2 on Ethernet.

Biggest concern is Satellite 2, as it is too far away from the Main Deco and Satellite 1 to connect via Wifi with good speed, it needs to be connected via ethernet

Note:

• Modem/Router does not seem to have a “bridge mode” in the settings, though I can turn off the DHCP server. This seems to be irrelevant though, given Adjusted Set-up 3.

• Ethernet cables between the rooms are around 20 to 30 meters long each. There are two of them. This also seems to be irrelevant as the switches connected to them don’t seem to be having any problems.

• Not included in the diagram are the phones, laptops, etc. that were always connected via wifi.

Initial Setup:

Initial Problem:

Satellite 2 gets disconnected (red blinking) after a few hours/minutes and does not automatically reconnect. Restarting the router sometimes works, sometimes does not. Can be reconnected by moving it out of the room and closer to Satellite 1 and then moving it back. After this it will still get disconnected after a few moments.

Adjusted set-up 1:

• Added a second switch (Switch 2) so that Internet connectivity to the Macbook does not go down if Satellite #2 gets disconnected.

New Problem 1:

• Both satellite decos now get disconnected (red blinking) and can’t be reconnected easily.

• Everything else connected to each switch still seems to have connection, only the Decos are having problems.

Adjusted Set-up 2

(There were several set-ups I tried before this one, but I can’t recall them all and they all didn't work)

• I removed Switch 1 entirely (as I thought it was the problem) and connected 2 ethernet cables using an ethernet coupler (basically making 1 long cable).

• Satellite 1 is now connected to the Main Deco via Wifi and has no problems at all.

New Problem 2:

• Satellite 2 still loses connection (red blinking), even though the Macbook connected to the switch still has connectivity

Adjusted Set-up 3

• Switched the Main Deco to AP mode

• Connected Satellite 2 directly to the ethernet cable, basically connecting it directly to the modem

New Problem 3

• Satellite 2 still loses connection (and obviously the switch as well)

Current solution:

• Made Satellite 2 it’s own Router (made a new network for it in the App) and it works fine, though obviously it's no longer in the mesh network.

TLDR:

Satellite 2 loses connection when on ethernet. Not sure what I am doing wrong or will I need to wait for firmware update to fix the issue.