They both work, however not straight away so perhaps this is what happened: you type MAL but got M for Malta instead (or MA for Marocco) so MAL needed to be typed again. Or perhaps you typed MNE and got M for Malta, then typed MAL and got MA for Marocco, so both Malaysia and Montenegro were left out...
e.g GBZ - Gibraltar
GBM - Isle of Man GBJ - Jersey etc