You all still don't get it.
I see my opponent's time rolling back a few seconds again and again, while MY time keeps advancing.
e.g.
I have 15 seconds left and he has 3. His time counts down till 0.5 and suddenly jumps back to 3
and again, and again. This is not explained by connection problems. This is simply a cheat, or a bug at best. It happend not once, not twice, not ten times, not twenty, ........
It absolutely is explained by connection issues and/or lag.
You make your move and your opponent's clock starts, however, your opponent hasn't received the move yet. They then make their move, but their clock is still counting down on your side because your client has not received the move yet. As soon as you receive the move from the server, your opponent's clock is modified to account for that transit time and any forgiven lag.
That is the way the site works and the official clocks are kept by the server and can't be hacked by your opponent.
https://support.chess.com/article/423-why-did-the-clock-times-suddenly-change-the-clocks-seem-broken
You all still don't get it.
I see my opponent's time rolling back a few seconds again and again, while MY time keeps advancing.
e.g.
I have 15 seconds left and he has 3. His time counts down till 0.5 and suddenly jumps back to 3
and again, and again. This is not explained by connection problems. This is simply a cheat, or a bug at best. It happend not once, not twice, not ten times, not twenty, ........