is adaptive noise immunity enabled in your config?

No. I'll enable it and check if my wlan is unstable. So far so good.

I upgraded to 6.45.1 and 5ghz is running and visible for 3 days. It lasts only for 1 day before. Is the issue fixed? Can someone confirm? Yep, running for 5 days or so. But maybe "adaptive noise immunity" disabling helped also. I didn't change anything in config. Just upgraded routeros.

I upgraded to 6.45.1 and 5ghz is running and visible for 3 days. It lasts only for 1 day before. Is the issue fixed? Can someone confirm?

First Mikrotik device I bought and definitely the last one. My 5ghz wlan works max for one day. Then It disappears. Latest stable firmware. I should've bought Ubiquiti instead. Wireless device with unstable wifi like the RB4011 one is unacceptable.