How to get rid of drops in internet speed?

Question

Computer networks

Greetings! There were some drawdowns in the speed of the Internet on laptops. That is, practically any pages open for 1-2 minutes, although after the page has loaded everything becomes fine (on this site). The problem is observed only on this device and does not depend on the browser and the type of connection (wifi / lan), which leads to the conclusion that the problem is of a software nature. I did a full system scan with the built-in windows antivirus - 0 threats. No torrents or programs using the Internet other than the browser are running.

The screenshots show how jerky the Internet is.
Notebook Xiaomi Mi Notebook Pro
Windows 10 corporate - 1809, build 17763.55
Main browser Chrome 70.0.3538.77
Please tell me which way to dig?

Answer 1

The problem was indeed the extension, as Yan suggested. The culprit turned out to be friGate3 proxy helper, although before that it worked like a clock and turned on only on certain sites (not on those that were stupid). Now I'm looking for a good replacement for him. Thank you all for participating!

Answer 2

The screenshots show only how the data passed through the network card of the laptop. There is no way to see how they should have passed. Such graphs are quite normal, for example, when periodically exchanging small amounts of data.
Start by testing your network throughput, for example with iperf. Then check the download of a large file from the Internet.
Naturally, during tests, other load on the network and the Internet should be minimized, ideally removed altogether.