Why is the router dropping connections?

Question

Computer networks

Hello.
There was a problem, I do not know how to solve it.
There is a house, 3 floors.
A twisted pair cable enters the first floor, enters the router (tp-link No. 1), further from it the cable goes to the 3rd floor and also enters the router (tp-link No. 2), from which 2 twisted pairs go to the second floor (to one point is airport express) and the second is just a PC.
And now about the problem:
Constantly something is wrong with tp-link #1. Stably once every N weeks, it starts to drop wi-fi connections, which leads to the purchase of a new router.
It looks something like this: connect to it, it works for a while (in <10 minutes), then turns off the device.
I'm tired of buying new routers, I want to figure out the possible reasons for this behavior of the router.
It stands on a hard surface, at a distance of ~ 1 meter, an introductory machine (380/240) + an electric meter.
Why do you think the router disconnects the device from the network?

Answer 1

It looks like you were not at all alarmed by problems with TP-LINK products on factory firmware and you bought the same rake.
And why didn't you try running ddwrt on the machine?
It is highly likely that your channel is set to "Auto" and there is interference with other channels. The router goes to a channel not supported by your client equipment. Or just changing the channel too often. Try setting the channel manually.

Answer 2

a couple of leading questions. comes from the street twisted pair? how far is the breakpoint?

Answer 3

In total, the problem was really that the channel was in the car. Switched it to 3, everything started to work stably. Thank you.