Hi all,

I’m looking for some advice on a Deco wired backhaul issue that’s been difficult to pin down.

Setup

• TP-Link Deco mesh (multiple units)

• Main Deco connected directly to router

• Ethernet run from house to shed (new build)

• Unmanaged gigabit switch installed at the house

• Shed Deco intended to use wired backhaul

The problem
The Deco in the shed consistently connects via wireless backhaul (shows another Deco + 5 GHz as signal source) instead of Ethernet.

What works

• A laptop plugged into the shed Ethernet point gets internet without issue

• I've swapped the Decos around and all work when connected to the router directly with a wired connection and if in close proximity pick up the wifi 

• The main Deco always shows Ethernet as expected

What doesn’t

• The shed Deco will not use Ethernet over the house→shed run

• Other satellite Decos also tend to prefer wireless unless connected directly at the router

Troubleshooting already done

• Confirmed latest firmware on all Decos

• Power-cycled everything in correct order

• Factory reset and re-added the shed Deco

• Installed an unmanaged gigabit switch at the router

• Tested with brand new Cat6 patch cables

• Tested the shed run with a laptop (works)

• Electrician tested continuity with an RJ45 tester (all 1–8 pass)

Despite this, the Deco still refuses the Ethernet path and falls back to Wi-Fi.

Current thinking
The Ethernet run is live but may be borderline for Deco wired backhaul (termination quality, pairing, etc.). Re-terminating the wall points is the next likely step, but before doing that I wanted to ask the community:

Questions

• Has anyone seen Decos reject Ethernet even when laptops work fine?

• Are there any Deco-specific settings, diagnostics, or tests I should try?

• Is there a known difference in how Decos validate wired backhaul vs normal client devices?

• Any other troubleshooting steps worth trying before re-terminating the cable?

Was thinking that perhaps i could order a TP-Link EAP653 (wired-only access point) to see whether it behaves differently on the same Ethernet run.

Any advice or suggestions would be very welcome.

Thanks in advance!