RT-AX88U 5Mhz doesn`t work

[Gos]

Greetings. I bought RT-AX88U recently, installed the latest firmware from Merlin and ran into a problem - after some time it stops distributing 5MHz Internet. Although 2.4Mhz continues to work. I attach the log.

 

[L&LD]

Welcome to the forums @Gos.

There is no log attached. Do you mean the 5GHz band?

What is 'the latest RMerlin' firmware, for you? Specifically?

After flashing RMerlin firmware from stock, did you do a full reset to factory defaults (see link below) and then perform a minimal and manual configuration of the router to secure it and connect to your ISP?

[Wireless] ASUS router Hard Factory Reset | Official Support | ASUS Global

It would also help to specify what options, features/scripts, and other customizations you have done past defaults to your router.

 

[Gos]

Hello @L&LD.
I attach the file again.
Firmware version 386.4_0.
Yes, I did a reset.
Maybe the reason is automatic Wi-Fi settings?
Currently, I have set the manual settings and am watching the work.