6E / 6GHz band not broadcasting on Satellite Node with Ethernet Backhaul + AP Mode - ZenWiFi ET8 (RT-AXE95Q)

[JohnyR]

Router Model Affected
RT-AXE95Q

Firmware Version Affected
I believe from 3004.388.9_2-gnuton to 3004.388.11_1-gnuton0_beta1

Is this bug present in upstream Merlin releases too?
IDK

Describe the bug
The satellite node with ethernet backhaul does not broadcast the 6GHz / 6E band when set to AP mode.

I've tried multiple variations of disabling and enabling ethernet backhaul, changing the backhaul connection priority, etc., and nothing ever seems to work. I've obviously tried factory resets and starting from scratch.

Here are my notes for previous builds where I managed to eventually get it to work.

The version after 3004.388.8_4-gnuton1 aka 9_2 does not broadcast 6E at all. 
I read in a thread that the stock Asus firmware after January 2025 broke 6E again, and 9_2 seems to be based on a version released after Jan 2025. 
TL;DR- use 3004.388.8_4-gnuton1 until further notice.

To get 6E broadcasting from the satellite node, do the following:

1. Factory reset node (power off, hold WPS button, power on, power off) and keep it off
2. Factory reset main router
3. Configure the main router, or upload the default config file in the directory. This config basically contains:
	- AiMesh > System Settings > Ethernet backhaul disabled
	- I temporarily enabled and then disabled smart connect so that I could set the 6 GHz frequency to be used as both fronthaul and backhaul. I first set it to backhaul only, saved, then set it back to both, saved. Then, I disabled smart connect entirely. 
		To me, it seems like this setting is set to fronthaul only on fresh installs yet the UI shows the wrong select option (i.e. both)
	- Configured Wi-Fi channels, SSID, professional settings
4. Reboot the router via the Reboot button up top
	*** DO NOT USE THE REBOOT OPTION IN AIMESH > SETTINGS > SYSTEM REBOOT. I think this messes with the AiMesh setup TBH
5. Power on the kitchen node and wait for it to connect (it should eventually connect)
6. Reboot again just for fun?
7. Configure the client names using the list

Expected behavior
Both main and satellite nodes to broadcast 6GHz / 6E.

Connection diagram, if it matters

                           ---> Main AP (WAN port)
Edgerouter ---> Switch ---| 
                           ---> Satellite AP (WAN port)