Hello, I have Mi Band 4 from 1 week now, but the battery life is really really bad. I use the default watchface, Viber notifications, Call notifications, low brightness, and sleep assistant, but the battery life is around 2-3 days. I have around 10 incoming calls and 30-40 Viber notifications. I stopped the Viber notifications, but still 4 % drain for around 5 hours. It is with 188.8.131.52 firmware and I did factory reset twice. Do you have a similar problem?