Internet connection problems

Such a problem for the last 2 months: the Internet periodically slows down sooooo on the laptop and other devices. Everything is ok on the hospital, it is connected via a cable. At first I sinned on the router, bought a new one, but the problem has not disappeared anywhere. I don’t know what to do anymore, because it’s impossible not to play, not to sit normally on the net. Constantly, either the signal drops to 0, or it simply turns off the Wi-Fi.
And I also noticed that at night and early in the morning everything works for 5+