I think the move dragon darts should hit its target twice, and if there is more then one target (this would only be in effect for 2 Pokémon max) it either hits one target twice or hits both Pokémon once each.
perhaps it only hits once in rise because of its strange mechanic where it can hit multiple targets like an AoE move. There are a number of additional move effects that don't function yet in rise; a fix for a single move exclusive to a single pokémon that is currently of very limited availability is probably not high on the list of priorities.