Last night I fixed this, at least it's working so far. I opened the Bluetooth function on my phone, then I turned my Fitbit off (which I verified by watching the Fitbit switch to "not connected" on my phone. Then it seemed to come back on by itself. I opened tha Fitbit app and switched my sync function in settings to "sync all the time" and all of my old info came back after a few minutes. I turned it off and was doing manual syncs, but I missed a few days. Maybe there was too much info for the unit to download in the manual sync mode. With sync all the time I suspect it had enough time to do what it had to do. Not a tech guy, so this is just a thought. Anyway, it's working so far.