Tormented by ping when playing on a local network. What could be the problem?

Question

Computer networks

We play co-op games with friends online, we all live in the same city, literally within a radius of 1 km from each other. All have one provider, a local TTK representative. All have the same speed of 100 Mbps. I never host. The host always uses the start of the server in the game itself, i.e. we play essentially locale. But everyone has 80 ping, I had a record today, 400! Keenetic kn 1711 router, QoS enabled, good router. The computer is connected directly to the router using a cable. What could be the problem and how to solve it.
PS I ask the question because it seems to me that the problem is still solvable, all the equipment is almost identical for everyone, and only I have ping.
PPS Cloudflare Speedtest shows ping 70 to server in Moscow, Speedtest shows ping 3 to local server
An interesting observation: Cloudflare Speedtest shows a terrible picture of 6 mbs, while at the same moment a friend shows 108, but on the router charts at this moment you can also see 6 mbs, while when working, for example, a torrent, on the same charts maybe 90 mbs, maybe the router slows down certain packets?

Answer 1

Well, the culprit was found, after my dances with a tambourine and dances of the provider, Windows turned out to be the culprit, as usual. In my case, the receive window auto-tuning feature was disabled by default. After turning it on, the Internet speed increased 10 times, and from 6 mbs it became 66mbs, a miracle and more!
Here's how to enable it: netsh int tcp set global autotuninglevel=normal

Answer 2

If the computer is connected to the router via Wi-Fi, then it will work.

Answer 3

If the ping is consistently high, there may be a problem with the hardware.
But if the ping is also unstable, then there is a high probability of a problem in the wires.
And maybe you have some kind of Trojan sitting and loading the network?

Answer 4

turn off torrents when playing ... the
city is not a local network
check the patch cord to the router for ping losses
ask them to perform a ping and MTR check to your PC