Weird "Move Times" Bug

Sometimes, when you replay the moves with the "realtime" mode, a weird glitch happens. I think what happens is that each move takes the time of the following move of the opponent. Example is this game G1gI9pjZ . Run in realtime, and noticed the move times graph.

Ok, I think it only happens because it is a thematic game, and the first move is by black.
This is an example of a thematic game, and the first move is by white G3IHtsIW , and there is no bug.