To provide some context with my network map, my X60 is "Study" which is connected via ethernet backhaul at the furthest end of my house (I ran an Ethernet cable there for my PC previously). The "Bedroom" and "Hallway" are both X20s, the "Bedroom" is located on the second floor and "Hallway" connects to "Study" to expand the coverage at the back of my house. The X80 is the "Living Room" which "Bedroom" connects to as it is on the same side of the house. The X20 is on the second floor which has weak 5GHz and once "Hallway" connects to "Bedroom" throughput drops down to 2.4GHz speeds. "Study" is only one wall and one door away in my hallway to serve the back rooms and "Hallway" doesn't connect to it even though the "Specified Connection" screen shows 2 out of 3 green bars. Most of the time, "Hallway" just flashes red and the app can't detect it, sometimes it picks up the weak 2.4GHz signal from the "Living Room" which is even further away than "Bedroom".

The only way for me to select the "Study" as "Preferred Signal Source" for my X20 is to first remove the X60 as my Deco then add the X60 back and once the X20 reconnects to "Bedroom" only then I can select the X60 which only then it reconnects back as the source.

I am beginning to suspect that this is a possible firmware bug with the X80 and how it handles hand offs when there are different Decos with different speeds (the X20s are AX1800 and the X60 is AX3000) as I didn't have this issue when I was using my previous X20 as the main node. But for additional information, the security is WPA2/WPA3 with "Fast Roaming" set to Enabled (eventhough I tried toggling it on and off) and the X60 was recently updated to "1.6.12 Build 20260513 Rel. 20500" (3 days before I obtained the X80 to replace as the Main Deco) but it has always served as the ethernet backhaul node with no issues so this can't be the cause. Another thing to note with the X80 is how it seems to hold onto devices longer in 5GHz eventhough the app says that the signal is poor for a specific device which I hope is not a side effect of the missing Beamforming option which was an option on my X20 when used as the main Deco but not the X80.

Other issues to note is that the "Network Optimization" feature in the Deco app for the X80 doesn't work for the 5GHz band as every time I used it, it reverts the channel back to 36 which is the most congested channel in my area and says its "Perfect". But when I reboot the network as performance decreases, it selects the uncongested channel 44 which immediately improves performance for the still active nodes. Furthermore, my previous X20 node regularly connects to the 149 to 161 channels instead bypassing congestion. This is disappointing as the X80 was considered the second best Deco other than the tri-band X90 for the WiFi 6 range.