http://replay.pokemonshowdown.com/pu-513830822
turn 34, i clicked trick with my itemless mr. mime against a metang holding an item. the move failed. earlier in the game, i had tricked my choice scarf onto a clefairy, also holding an eviolite, which proceeded to knock off the eviolite my mr. mime stole. in-game, trick only fails if neither pokemon is holding an item, and it doesn't matter if the items are the same.
ive noticed this happen several times recently, but this is the first time it happened during one of my games. it seems to be a recent bug, ive been able to trick items purely away before.
this game is gen 6 pu. i don't know if something in sun and moon changed trick's mechanics, but if it did, its affecting gen 6. according to bulbapedia, trick's mechanics were not changed, but its bulbapedia.