RBE771: 6th wired satellite missing / 5th Config Sync

Hello,

I am seeing what appears to be a reproducible issue with my Orbi RBE771 running firmware V10.5.20.10.

Hardware

Router: RBE771

Satellites: 6 × RBE770

Firmware: V10.5.20.10 on router and all satellites

All satellites use Ethernet backhaul through unmanaged Netgear switches in a star topology (no daisy chaining).

Observed behavior

With 4 satellites connected:

Attached Devices correctly shows all 4 satellites as Wired / Good.

With 5 satellites connected:

Attached Devices correctly shows all 5 satellites as Wired / Good.

After adding the 6th satellite:

One of the existing satellites changes from Wired / Good to Wired / Config Sync.

The 6th satellite does not appear on the Attached Devices page.

The Firmware Update page correctly lists all 6 satellites running firmware V10.5.20.10.

Network performance

Despite the display issue:

Wi-Fi performance remains excellent (approximately 1 Gbps beside each satellite).

Roaming works normally.

Router logs show no satellite disconnects.

The network continues to operate normally.

As another test, before powering on the 6th satellite I had only about 2 bars of Wi-Fi signal in that room. After powering it on, the signal increased to 3 bars, indicating that the 6th satellite is providing coverage even though it does not appear on the Attached Devices page.

Troubleshooting already performed

Factory reset of the router and all satellites.

Rebuilt the entire mesh from scratch.

Updated every device to firmware V10.5.20.10.

Verified Ethernet backhaul.

Using unmanaged Netgear switches.

Has anyone else experienced this with an RBE771 using six wired RBE770 satellites?

Specifically, the 6th satellite appears on the Firmware Update page but not on Attached Devices, while one of the existing satellites changes Wired / Good to Wired / Config Sync after the 6th satellite is added.

Any suggestions or confirmation from others running six wired RBE770 satellites would be appreciated.

Thank you.