Can't sync with my Iphone 7 (updated to version 11.0.3)

[Mandy_Zheng]

Since I updated my Iphone 7's IOS version to 11.0.3, I found it can't sync with my Alta HR. 

[MarcoGFitbit]

Hello @Mandy_Zheng, have a warm welcome to the Fitbit Community, it's great to have you on board. 

If your Zip is not syncing correctly with your phone, please try the following steps:

1. Restart your Alta HR
2. Restart your phone
3. Make sure you have a strong WiFi signal
4. Make sure there are no other Bluetooth devices around that might interfere with the syncing process.
5. Try to sync your tracker again.

If your tracker is still not syncing correctly, my best recommendation would be setting up your tracker as a new device. Don't worry, none of the information previously stored in your account will be deleted. 

To set up your tracker as a new device:

1. Go to the Bluetooth settings on your phone and check if your tracker is on the list of paired devices. If it is, tap on it and select Forget this Device.
2. 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"
3. Choose your tracker and follow the onscreen instructions to continue
4. 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.