Why has ping increased over the local network (Wi-Fi)?

Question

WiFi

The situation is this:

• At one end - TP-Link Archer C3150 router
  
• On the other - Wi-Fi network card in PCI-Express in PC
  

Before that, there was a TL-WDN4800 , and there were no questions for it - the ping on the local network is almost always 1 ms. Almost. Because with any torrent download, local ping (!) increased to almost 20% packet loss. Whatever I did with torrent clients, and reduced the number of requests, connections, peers, and cut the speed, and reduced the number of simultaneous downloads - nothing helped.
I replaced this network card with a Fenvi v1.02 from AliExpress based on the Intel AC-9260 chipset , and this network card is great! Since this is an assembly kit, I mounted it like this:
However, a problem arose: ping, regardless of the load on the network card, always happens in two positions: 1-4 ms and 18-25 ms:

C:\Users\Kenya-West>ping 192.168.0.1 -t

Обмен пакетами с 192.168.0.1 по с 32 байтами данных:
Ответ от 192.168.0.1: число байт=32 время=3мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=3мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=1мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=15мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=2мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=3мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=1мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=4мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=10мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=25мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=1мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=1мс TTL=64
Ответ от 192.168.0.1: число байт=32 время=2мс TTL=64

What is the problem? The previous Wi-Fi network card in quiet mode always had 1 ms ping over LAN...
Here's some food for thought:

1. The system configuration has not changed: the same fresh Windows 10 April 2018 Update
   
2. Wi-Fi router in line of sight over a 5 GHz channel (40 MHz width, channel 16, or something), and its configuration has not changed
   
3. The drivers for the network card are updated, version 20.70, but I tried the old ones too - damn the same problem
   
4. Everything is fine with the system.
   
5. I use Steam, uTorrent, Skype, Discord, a bunch of Electron apps. I use the computer for design, motion design, video editing, 3D modeling, web development, laning machines, study, office work, programming, entertainment and streaming all of the above using all the protocols that exist in the world (well, except for `gopher:// `)
   

Answer 1

Wifi is a thing too dependent on the environment. There can be any number of reasons, you can't calculate everything.
A neighbor bought a router, the phone lies unsuccessfully, a signal with a reflection came, Windows sent the metric. Random 25ms is fine.
The most reliable way is to treat the cable. Especially considering that you actively use the Internet.

Answer 2

You heated up something in the microwave, and the whole WiFi network lags.

Answer 3

Reflection of the signal of Chinese adapters, radio frequency interference, try changing the channel, update the driver