Why does wi-fi speed drop after a certain time?

Question

linux

After 15-20 minutes of work, the Internet speed drops on Ubuntu 18.04. The system has been updated.

Answer 1

Here you need to check on other devices, if it only crashes in Ubuntu, then this is most likely the adapter overheats on it, if on all devices, then the easiest thing is to change the router :)

Answer 2

The system checks the availability of all repositories or the presence of updates + software updates. Or some programs are eating the Internet