fix the timer!!
The clock on the client side is not the official clock. That is kept by the server and should update after each move.
Lag and disconnects can make the clock change and it is possible that the display staying at 0 could be a bug. If you look at the game in your archive on the website, you will see that their clock was never at 0.
https://support.chess.com/customer/en/portal/articles/1444849-why-did-the-clock-times-suddenly-change-the-clocks-seem-broken-
Still, the timer readings are misleading. I can't rely on them to assess how much time I, or my opponent, have left. Nor there's any way to foresee how the timer will behave. Will it suddenly jump from 2 seconds to 0 for me, or just keep adding seconds to my opponent when his time has run up because of a "dynamic lag correction"? No way of predicting this. And how am I supposed to play time-controlled games if the time measurement is haphazard like that?? Especially in bullet. This is quite annoying. I wonder if I sustained some neurological damage because of your timer, would I be able to sue you?