Epic Launcher - Can't go online

since i downloaded and installed Epic Game Launcher with Fortnite i can’t reach the server. By reading online forum i see that when i login on Epic Launcher i can be online with green icon, but everytime i login i’m red and i can’t turn online (green). If i login this account with another pc there isn’t any problem. after if i try to play Fortnite, it can’t reach the server when i insert the login credentials.
How i can resolve??