Cannot sync with the candy crush soda app on Android tablet

Hello, I hope someone can help us. I help my mother in law who loves playing the candy crush soda saga. She plays it on het Android tablet. According to her, while playing candy crush soda (the app) her tablet crashed unexpectedly and when she restarted the tablet and the game, she lost all her levels. I've tried every solution I can find here but I can't get her levels back for her. I synced with Facebook and now it keeps saying "can't sync anymore because you already synced". The strang thing is, when I go to king.com/games and go to candy crush soda and log in via Facebook, she has all her levels. But when I open candy crush soda via the app (from play store) then she has lost all levels. So it doesn't seem to sync with the App. Can someone help please??

Thank you so much!