I just lost on time even though I played a move before my time ran out! My screen showed my move on the board and five seconds on my clock at the time of moving.
It showed that board state for a few seconds, but then told me I lost on time (and then in the game review screen my last move was not on the board).
This is very frustrating! (It was the end of a great game and I was winning against a high ranked opponent)
OGS server could wait a little longer before declaring a loss on time to try to ensure it is sync’d properly to the player’s local browser to avoid this happening, perhaps? I’m not sure of the best solution on the back end, only that this is a seriously detrimental bug that must be fixed.