FWIW, Moncada has the second most called third strikes on pitches that were outside the zone in MLB with 9 such blown calls. Matt Davidson is first with 11. For the sake of context, he's also struck out looking 22 times on pitches *inside* the zone, which ranks highly. Still, you're looking at nearly a third of his strikeouts looking ending on a blown call by the umpire. For more context, he's had 5 pitches in the zone called balls with 2 strikes (56th highest in MLB), so this isn't merely an artifact of him taking a lot of pitches. League-wide players on average get many more 2-strike pitches in the zone called balls than the opposite kind of mistake because the strike zone as it is typically called by umpires is smaller than the rulebook strike zone. And as one last fun fact about Moncada's struggles with the umpires, he's had 5 occasions in which a 3-ball pitch outside the zone was called a strike, 3rd highest number in the league. He's only had the inverse happen 2 times, making him one of the unluckiest full time players by that measure as well.
Side note: Davidson has only struck out 14 times looking on pitches inside the zone, meaning it's about a coin flip when he's called out looking whether strike 3 was in the zone or not.