That's not a bug. It's how the scoring system works in Arena tournaments.

You scored 1 point for your draw with vasigo from round 4. Now, (unfortunately) you lost every game after that until your next draw. That second draw combines with the first one to make a streak. The streak of draws can only be broken by wins, which (unfortunately) you didn't have. So, according to the rules, only the first draw can give you a point unless the next drawn games last until move 30, in which case you would get a point for each one of them. Since your second draw (the one with agreste) only took 17 moves, then it didn't yield a point for you. The lesson is: if you are going to draw a game, make sure to reach the move 30 first to ensure a point.

BTW, why aren't you playing the Chess Brothers league on Sundays? We miss you there.