When my chick was about 8 or 9 weeks old I saw her start to scratch her ear and then fall over. Eventually over the day it got so she couldn't stay upright to scratch and she got very unsteady and finally just couldn't walk . I took her to an avian vet and though he couldn't see anything wrong with her ears he gave her baytril and I treated her at home twice a day with baytril and propped her where she could eat and drink. She could get around her old brooder by basically just trying and flopping. She recovered but then went crossbeak. She seemed fine until this week when she died unexpectedly. I can't connect her death with her condition particularly. I just wanted to suggest antibiotics. Good luck.