Greetings. This is something I have noticed on an Uno table, however it is possible it happens in other games too. When the game is over, the timer on ctrl t does not stop and keeps going as both the time for the current round and overall game. This goes on until of course a new game is started, thus restarting the timer. I believe that the timer should stop going after the game is over, thus allowing you to see accurately how long a game lasted. At present, even when a player wins it does not seem to affect the game duration time.
Thanks for your responses, and for making great and detailed statistics like these.

Just confirming that it's indeed related with all game tables.

Not tested it but if you pause a game would it stop the timer?

Just tried, and no the timer does not stop in round pauses either. Although a different bug, still related so good idea and nice catch.