Clearly this is a known issue, as I was recently was awarded points back due to server cheating, I’d like to say it is still rife and sucks!
That sounds like either lag or disconnects between you and the server (not necessarily a disconnect from your local connection).
Do you maintain both a wifi and cellular connection while playing? If so, devices can switch between those connections, depending on what the OS sees as the best connection at any time, which can cause packet drops and resends, short disconnects, or other lag as it switches between the connections.
Regarding any refunds you got, that would be due to Fair Play closures. Your opponents can't impact your connections or clock as the server handles both.
https://support.chess.com/article/648-what-do-i-need-to-know-about-fair-play-on-chess-com
Clearly this is a known issue, as I was recently was awarded points back due to server cheating, I’d like to say it is still rife and sucks!