unstable connection

Hello, last week I've a crazy problem with my connection. It shows that I've internet but when I load web pages I get "The connection has timed out" 3-4 times then page loads slowly. Discord sometimes loads sometimes no, steam connects for few minutes then goes off then can work for 1-2 hours...

I have been trying to fix an issue regarding this ping and packet loss. I am on ethernet through powerline, connected to a Router/Modem Netgear C6250. I am on powerline adapters, but the issue still persists while plugged directly into the router, as well as a USB Wi-Fi adapter. Before a few...