Help

So my fiance doesn't play Genshin all that much, but we finally were able to get it set up on her Xbox. She had just logged in and ALL of her progress was lost. She's a relatively new player, and was in the Interlude quests after Liyue. And now she's back in Mondstadt with only Traveler, Amber Lisa and Kaeya and we have no idea what the hell could've happened. Some insight would be really nice as to what might've happened here.