Move your mouse over your score at the bottom of the screen to see the breakdown of medals. If there is at least one game on which you have only bronze medals, then your score for that game is 0 and the multiplication will be 0. If, after this check, you do find a bug, please share the replay of the game so we can check
Is there any bug when calculating the score? The instructions indicate that score is based on this formula
mini_game_score = nb_silver_medals + nb_gold_medals * 3
However I have zero points although I have 4 gold medals
This confused me for some time - the explanation is that you have to have at least one gold or silver from each of the different types of mini-game i.e. the gold/silvers score from hurdles is multiplied by the gold/silver from archery by the gold/silvers from cycling etc.