How to set up a 5 Ghz Wi-fi network in a router so that it does not turn off?

Question

Network administration

I have an ASUS RT-N66U router in a room across the corridor (2 walls) and on my machine TP-LINK TL-WDN4800
Problems arise with a 5Ghz network. Symptomatic - it just cuts off and cannot connect back. The adapter, meanwhile, is changing to a 2.4 Ghz network - but it is slower and conflicts with the wireless mouse (the mouse starts twitching)
I can not find a solution to this problem.
The following has already been tested and did not help:
Firmware, both original and from Merlin .
The power of the router changed in hardware
. Specific and automatically detected channels were also set.
In desperation, I already tried and even poke some obscure things like on and off (for example, a short / long preamble, although I don’t even know what it is)
At the same time, the 5 GHz network sometimes disappears altogether, sometimes it has 3-5 sticks (but it doesn’t connect anyway - it tries - but an error - it’s just that windows can’t connect to this network.
Rebooting through the admin panel does not help. Rebooting manually with the button on router - helps from time to time from time to time.As a rule, if you start work, then the network
works.I suspect overheating, but why then does the 2.4 ghz network always work and why does not the power decrease (for slight heating)
help ? except for technical texts that are really difficult for themselves, which require deep knowledge of networks, I still have not found an answer.

Answer 1

Doesn't work on only 1 receiver? Is there another client with 5Hz? Phone, for example.
Obviously, the problem is either in the transmitter or in the receiver.
Could be a factory defect. In general, the problem with routers is HUGE. I've already gone through a dozen - all of them, something doesn't work. While pah-pah Zyxel Keenetic Ultra works on 5 (there were glitches with flash drives, but they seem to have fixed it in the latest firmware).