This article might help:
https://support.chess.com/article/213-how-do-i-fix-my-disconnect-lag-issues
Sometimes a disconnect happens and you don't realize it until too late. Or since you're a standard member and get ads, one of them might have bad code and be causing a memory leak. Or so I read in another thread. More likely not, but you never know. Even without the ads chess.com is a bit of a memory hog so clearing your browser cache regularly is a must. Good Luck!
https://www.chess.com/live/game/4359133441
https://www.chess.com/live/game/4356023385
I've been automatically aborted from the game twice since yesterday! Is this some kind of cheat? Or is it just another shxxty chess.com's server problems...