Lately I am getting this weird problem with internet. If I keep my system idle for few hours and then start browsing internet, some websites won't load. If I click speed dial on firefox, nothing happens. I switch on vpn or use different browser to open that website, even then it won't load. Network diagnostics says no problem. Even my router settings won't open in any browser. Only way is I restart my PC and then everything works. What could be the problem ?