The opponent's time ran out but I lose the game with more than 30 seconds in favor

, the opponent's clock was stopped and mine kept advancing

Just looking at the 1st game you shared... They appear to have been premoving, which can lead to moves not taking any time off the clock. And according to the analysis page, after their last move before your own time ran out they still had 0.6 seconds remaining. Curiously, there's an additional entry after their last move indicating their clock went to zero. I have a guess but am not totally sure what that's about. Maybe others can provide a definitive answer.

I had a similar issue, but not quite the same, the game lichess.org/0pHCEzDZYJmV we were almost both out of time, less than 10 seconds and then I lost by time out my opponent having 48 seconds suddenly ?
Maybe it is due to connection issue, but on my side, their side, lichess side ?
:(