For your issue, I would recommend you to use your band and drain its battery completely, Then charge it till 100. Then factory reset your band and then reinstall the app then you should be able to connect the band. Now try to update it. Tell me what happened after this procedure
Ok first you should check if your mi band is working correctly. 2nd I would like to know how many times you have tried to update it. Have you tried changing devices for your update. I think the problem is with the band's firmware, which is unable to recieve and install update. Also could you...