Bug with Black Dragon level up

I removed phone battery for some reason and when I turned on the phone again it had returned to a date of 2013 or something like that. Then I opened the game (without knowing my phone had changed the date) and I saw that stamina bar and dragon level up needed 20K+ hours. So I figured the phone date had changed. I closed the game fixed my phone time and date, reopened the game stamina bar fixed but the dragon level up is still messed up.