I have been playing this game for years and just noticed this bug recently. I don't know if it's a new bug, or I just never noticed it before:
In the score breakdown, the game is crediting you with one less investigator turn than the actual number.
I noticed this in games where I go against Yig using four investigators. There are no clock advance events when you play Yig, so if the fourth investigator in your team takes the last turn, the number of turns must be a multiple of four. But in the last game I played, the 4th investigator took the last turn, but my turn count was displayed as 15. In the game before that, again the 4th investigator took the last turn, but the turn count in the score breakdown was 19.
I haven't noticed yet whether the numbers are off when the last turn is taken by one of the first three investigators. Those last two scores just kind of jumped out at me because obviously they should have been multiples of four.
At a guess, I would say that the logic to check for end-of-game comes before the logic to increment the turn counter, so the last turn is never counted. Possibly also there is some issue if the last turn of the game is also the last turn of the day.