Why does wifi signal die?

Question

WiFi

Hello!
Having moved to a new apartment, we faced the following anomaly. Within a short time wifi stops working. It is the wifi signal, if the Internet is connected to the modem via cable and it is stable.
So the Promsvyaz modem (aka ZTE) worked for a week, Acorp for about a week, and now the third modem (Promsvyaz) is working very poorly.
It is worth noting that all modems work very poorly: all devices (smartphones, computers, TV) do not want to connect automatically - you must always explicitly indicate that you need to connect. Very often it breaks the connection, it also often cannot connect, although it sees the network.
It seems that the signal is being jammed by something, the question is what and how can this be found out?
It is also worth noting that the apartment has an alarm system, and right under the apartment is a regular grocery store.
Thank you.

Answer 1

check with the inssider program if there is a signal overlap from the neighbors. Google the toaster, the issue of wifi signal comes up quite often

spoiler

Answer 2

Promsvyaz for signaling is some kind of anomaly. I'm going to see a colleague next week to see what the problem is. He also changed the modem.
This is a private house, that is, there is no interference from neighbors. According to him, as soon as 2 tablets are connected to WiFi, the laptop (3rd client) slows down and falls off.
A solution suggests itself - use Promsvyaz for the wire, for WiFi, connect another access point or router to the modem in access point mode.
At my house - Promsvyaz without signaling, 5 clients by wire and one via WiFi through 2 concrete walls - there are no problems.
Remind yourself next Friday - I'll tell you how it ended.

Answer 3

I will join the previous speakers, plus I will add 3 more points from myself.
1. There may be interference that InSSIDer will not see, for example, from noise generators, etc.
2. A weak client device also causes the entire channel to sag due to the repetitions that the AP will make.
3. IMHO, you can try to include MAC ACL in addition. If there are a lot of extraneous authorization requests...

Answer 4

Alternatively, manually change the radio channel number (channel number) in the router settings, monitor (Wi-Fi Explorer, InSSIDer, etc.) and select the radio channel with the best signal-to-noise ratio. Most likely, it is an overlap with neighboring signals.