https://support.chess.com/article/213-how-do-i-fix-my-disconnect-lag-issues
There are a lot of things that can cause lag and disconnects, from the client side to any of the connections between the client and the chess.com servers. The site servers are just a small part of that and most members play with no issues.
this is f*ing very annoying serious app issue! I HAVE VERY STRONG WIFI INTERNET CONNECTION (INFACT I EVEN TRIED 5G CELLULAR) STILL ITS GETTING DISCONNECTED. W/O ANY NOTIFICATION I KEPT LOOSING MY TIME. AND LOST MANY GAMES WHICH I COULD HAVE WON!! Chess app should fix this issue ASAP!!!! It’s really getting worst!!!!!!!!!!