I bought an old Fortnite pack that contains StW access but I haven't gotten anything in game

As the title says, I bought a cheap key for one of the packs that contains access to Save The World, it is a Xbox code so I redeemed it on the Microsoft site, it was everything alright, even the site told me that but when I got inside the game nothing happened, I tried logging in through Xbox cloud gaming and it doesn't work either. What's wrong? Does anybody know anything about that.

Update: the game created another account, I don't know how nor why and now I have to fucking switch between them when I want to change mode... It's something that happened before when I tried connecting my Xbox account but Epic said that they fixed it and now it happened again to the SAME ONE... Incredible, Epic won't even give me StW back to my main probably, I won't even try...