I need to add a behavior pack to my world but I import it and it shows up in other words, but not in the one I need it in. it shows old packs I deleted. I even tried uninstalling and reinstalling mc. I exported the world then re-imported it. still has those same old packs. tried doing it through realms but it won't work. 

edit: I can change it by exporting the world onto my desktop and changing it through the files but it takes a long time to do it and its really annoying.