Fairy Tail - Matchliller 3rd effect that read as follows “You can pay 500 LP; make the name of 1 Effect Monster your opponent controls become “Fairy Prince”. The cost part (paying 500 LP) works fine, selecting 1 opponents monster also works fine, but the monster don’t become a “Fairy Prince”. The other “Fairy Tail” cards that have the same effect (“Fairy Tail Ball” and “Weaver of Fairy Tales”) works properly and even change the monster type to Spellcaster (I assume is because “Tales of Fairy Tail” let you use one “Fairy Prince” your opponent control to fusion summon”).
Reproducing the Bug: A simple local match VS AI Bot should reproduce this bug, just have Matchlille on your field and a effect monster on your opponent side of the field.