Deck copy/paste not working

So I have over 200 deck lists. So with only 27 slots available, I switch out decks all the time through copying and pasting. Recently, this hasn’t been working properly. In my collection, the deck will be correct, but when I actually use it in a match, it will be whatever setup it was before the import. So far the only thing that works is just deleting the deck and importing a fresh one.