If still unable to upgrade, you may need to reflash the latest firmware in rescue mode.
Go to RT-AC86U official website and download "ASUS Firmware Restoration version 2.1.0.2". Also get prepare the latest firmware 3.0.0.4.384.81351.

First, you need to reset your router. So make sure you need to backup your router settings in the "save settings" feature inside your router. If you want to redo the settings manually, so just note down everything important such as unifi pppoe ID and password, port forwarding settings, wifi ssid, password etc before you proceed to reset your router.

The reset button, I think you should know what to do. Usually I am using a pen to stick inside the small hole of my router.

After you reset the router, put your router in front of your PC and use a LAN cable to connect to the PC, set your PC ethernet IPv4 default gateway as 192.168.1.1. So your PC local IP just set whatever you like as long as 192.168.1.xx.

So now, you need to switch off that router. Now use your pen and hold the reset button, another hand to power on the router. Keep hold the reset button until the power LED of your router start to blink off and on very slow. Now you can release the reset button.

Start ASUS Firmware Restoration tool and locate your RT-AC86U to flash the firmware into your router. After done, you may need to wait 5-10 minutes to wait for the router restart.

** How to ensure that your router in rescue mode? You can always open 192.168.1.1 with web browser to check."

Just select 'Unifi-Business' for ISP Profile

Hi yfyap69,

May I know is both of the router is on the latest firmware?

Thank you

What is the budget?

The GT-AX11000 will be the most effective combo with GT-AX11000 if budget is not a concern.
Just helped a family with the exact same issue and happened right after updating to the latest firmware.

Downgrade to the old firmware until ASUS fixed it.

Not sure, try it yourself and report back?

Hi, can you teach me how to downgrade the firmware? I'm using AC86u and having the same problem like you.

Hi yfyap69,

You can get a AiMesh supported router and configure as main router or add it as AiMesh node.

https://www.asus.com/networking-iot-servers...Fi-WiFi-Systems

Thank you

Hi yfyap69,

I would suggest you to use ASUS Router APP and setup the network as AiMesh network instead.

Thank you

Hi yfyap69,

Only by using ASUS Router APP you can setup AiMesh, if you still using Lyra APP. you cannot add AiMesh supported router using Lyra APP.

And we have stop supporting Lyra Mesh long time ago. If you check our website, we didn't mention Lyra mesh anymore, its all AiMesh.

https://www.asus.com/us/Networking-IoT-Serv...d-Systems/Lyra/

Yes, you will need to redo the setting.

Thank you

Hi yfyap69,

You can refer to the Youtube below on how to add the node.

Make the Lyra you want to add LED light is in white colour before adding.

https://www.youtube.com/watch?v=lfdIDxMLZuM..._channel=ASUSMY

Thank you

Hi yfyap69,

The number of node recommended is 5 including the main router if you connect it wirelessly.

https://www.asus.com/support/FAQ/1044191

As Lyra is no longer selling in the market, if you plan to purchase a new router with higher spec, then I would suggest you to make the new router as the main router and the Lyra as the node.

Thank you

Hi yfyap69,

Is all the Lyra is on the same firmware version?

Is the new Lyra is near the main router when you are adding them?

Thank you

Hi yfyap69,

May I know you are using the ASUS Router APP to do the setup? Does the APP show the node you have added?

The below link show the meaning of the LED light.

https://www.asus.com/support/FAQ/1033085/

Thank you