So i got my Macho brace from kanto, i forgot how i got it, but i have one and it helped me when I am doing ev training on kanto but i just noticed when I defeated elite four of kanto and entered johto, i was about to ev train my cyndaquil early and then tada i cant find my macho brace. I remember putting it on my backpack before entering johto. It just disappeared.
I also already checked my previous pokemons from kanto that is now locked and its not on any of my pokemon.