Hey @RobL2,

I believe that you need to configure the host connections separately, did you happen to only configure the credentials for the 2.4GHz, and not the 5GHz? Even if you normally only see one Wi-Fi name, you will still technically have two different SSIDs available.

We usually also recommend enabling the Smart Connect feature on your router when you are using the OneMesh feature as it provides a much better experience while roaming throughout your home.

  @RobL2 

I have the same issue on the 5GHz mesh like you.  I'm using BE800 + RE815XE with a weekly reboot schedule on every Mon early morning to optimum the WiFi conductivities and performance in the entire week.

When the RE815XE running v1.0.4 & v1.0.5, I noticed quite many times that the 5GHz mesh connection (never happened on 2.4GHz & 6GHz) between my BE800 & RE815XE was lost (the dimmed like your screenshot) in the Mon morning.  Sometimes the 5GHz band will be reconnected automatically by noon, but sometimes I need reboot my RE815XE manually then all 3 bands ok.  I've reported to CS but didn't get a solution.

Until applied the latest FW v1.0.6, my RE815XE has less 5GHz mesh failure, but still happened a few times.

* I'm using Smart Connect too, 1 SSID for Smart Connect and 1 SSID for 6GHz.