This has been an issue since January's update, for some, since December. They've pretty much ignored all our reports and complaints. They've made few vague statements about a team working on it, but rolling back an update doesn't take 4+ months.
The only option right now (besides returning your Fitbits) is to request a replacement device and not-update the firmware beyond the setup's required one. The device may record in a delayed way, but you'll get all the features we were promised.
