got internet connection but lose connection with chess.com

Connection to the Internet in general, or your local LAN, does not guarantee thet there isn't a disconnect of the client code with the back-end Live server.
If you are on the website, sometimes a tab/page refresh is enough to force a reconnect.
https://support.chess.com/customer/en/portal/articles/1444918-my-internet-connection-is-fine---why-am-i-getting-disconnects-
Something else that might help.
https://www.chess.com/blog/News/how-to-adjust-your-live-chess-connection