FW Update Issue from 386.3_2 to latest on ASUS RT-AX88U

Hi,
I am on a very old version by Merlin on Asus RT-AX88U.
Current Version is : 386.3_2
Latest Version is : RT-AX88U_3004_388.8

I am trying to update to the latest one but it doesn't work.
I've also tried to update to stock and it also doesn't work.
Do you have any idea why and suggestions how to fix ?

Thanks