The torch doesn't work in lockscrenn. Only by unlocking the screen. The problems comes from 5 or 6 updates ago! At least, In my mi5 prime. Please, try to fix it. I use a lot the torch.
HI. My 4s never had that problem. Actually, i have no bugs. I'm very satisfied. I only use developer official rom and use English language. Maybe you should have a defective hardware and should activate warranty. Já agora, és tuga?