This has been happening to me too whenever I first go onto Chess.com. Not sure how to fix it other than reloading.
Error 502

Link to game https://www.chess.com/analysis/game/live/67191723051

Link to game https://www.chess.com/analysis/game/live/67191723051
wut is dis perfuct gam

There were some issues this morning. 502 errors don't really need to be reported unless you're getting them for a specific action and everything else is working correctly.

Link to game https://www.chess.com/analysis/game/live/67191723051
You might open a ticket with support and explain that you refreshed. They may refund the rating loss.
I was playing a game and I refreshed and then this 502 error appeared. I lost the game because of this.