You can reset a Fitbit Flex to its factory settings as long as you have an official Flex charger and a paperclip or similar tool. Here's how to do it.

Tap the Settings app (gear icon) on your Fitbit device. Tap About or Device Info (if you see these options). Next, select Clear User Data or Factory Reset. Depending on your device, you may be ...

Fixes for drained battery, update issues, dirt, weak connections, and more Restart > clean connections > use a different charger > replace the cable > bring the phone closer. Check Bluetooth ...

Restart > clean connections > use a different charger > replace the cable > bring the phone closer. Check Bluetooth connection > disconnect other Bluetooth devices > restart Fitbit app > check for ...