When duels are played in a party game with multiplier set to 0, there are weird effects going on in the game summary afterwards.
This is an example:
Problems:
  1. Multipliers should not be showing, but R5 has multipliers, R6 has no multipliers, and then it continues in a weird pattern.
  2. Multipliers are being used to calculate the red numbers that are displayed that show how much HP the players lost on each round.
Note that it's purely a visual bug in the summary. The multipliers were not applied during the duel. This can be checked by doing manual calculations on i.e. R5 or R8.