Flex 2 not syncing with my phone.

[DempseyDog]

My Flex 2 has been working and syncing to my iphone perfectly until someone at work got a new one today. I'm sure that while she was programming hers, it messed up mine. How do I fix this??? I've tried everything suggested already. Now my Flex only shows a red light when I tap it and won't sync. FYI, it was fully charged this morning and tracking my steps.

Moderator Edit: Clarified Subject.

[MarcoGFitbit]

Hello @DempseyDog, thanks for joining us, it's great to have you on board the Fitbit Community. 

If you'r Flex 2 is not syncing correctly, please restart it, then restart your phone and try to sync again. If that doesn't seem to work, let's try to add your tracker as a new device to reset the connection between your tracker and your phone.

To set up your tracker as a new device:

1. Go to the Bluetooth settings on your phone and check if Flex 2 is on the list of paired devices. If it is, tap on it and select Forget this Device. 
2. Restart your phone.
3. Open the Fitbit app and tap on the Account symbol at the top right corner of the screen, then tap on "Set up a New Device"
4. Choose your tracker and follow the onscreen instructions to continue
5. When the app asks you to replace your current tracker, please replace it and continue with the process.

I hope this can be helpful, give it a try and keep me posted in case you need anything else.