Can't connect to some game servers, but internet works fine

Hello, I'm having trouble to playing game servers for 2 weeks. I have tried enabling upnp,`ipconfig /flushdns`, resetting modem, disabling firewall, checking integrity of files but somehow i cant connect to game servers. It's like it sometimes works and sometimes not. Like the games Genshin Impact, Fallout 76 and Elden Ring. What might causing this?