I have this issue too, on Galaxy S5, Android 5.0.2. My fitbit has never sync'ed reliably, and the widget contents are consistently 0 steps, mostly even after a successful sync. Because it eventually syncs successfully, I've put up with the flakiness.
However, this thing should not require Location information to sync via a Bluetooth connection. The app is nagging me to turn Location Services on, but if I keep trying, it does sync without needing Location turned on. So clearly it Doesn't need Location services to be able to sync, that is a lie.
The device itself seems fine, but the software which came with it, and particularly the widget, has always been dreadful. I'm waiting for a device I like more to come along. When it inevitably does, I will make the call. If the Fitbit software is still woeful, I will ditch the device, and I will not be back.