RT-AX88u mac address wlan 2.4 and 5 ghz equal

[paocube55]

Hi, I have this problem in my router RT-AX88u.
On the system status page, wireless MAC address are equal for 2.4 ghz to 5 ghz.
So basically the router doesn't work properly for the wireless part.
If I search for wireless networks with netspot I only see the 2.4 ghz network.
I have already tried doing hardware resets several times.
I installed Asuswrt-Merlin firmware which did not fix the problem.
Have you any suggest?
Thanks a lot

 

[degrub]

Is this a new problem after a firmware upgrade ?

Or is this a problem that started from the first power up / configuration of the router ?
If yes, was the router purchased new or used ?

What are the MAC addresses for the two radios printed on the box ?

 

[paocube55]

Is this a new problem after a firmware upgrade ?

Or is this a problem that started from the first power up / configuration of the router ?
If yes, was the router purchased new or used ?

What are the MAC addresses for the two radios printed on the box ?

I have this router since 2021.
I noticed that the wireless network suddenly wasn't working properly.

So I realized that the wireless MAC address are equal.
I then installed the latest version of the Asus firmware and then the corresponding Merlin version but without success.

The label on the router show only the hardware MAC address.