New iPhone 8 Plus is unable to sync with Alta HR.

[Fitnanaof3]

I just upgraded my phone to a iPhone 8 Plus now I can’t get my fit bit Alta hr to recognize new phone 

Moderator Edit: Clarified Subject.

[SteveH]

Do you still have your old phone? If so, make sure it doesn't still have a bluetooth connection to the fitbit that might be blocking connection to the new phone.

[MarcoGFitbit]

Hello @Fitnanaof3, thanks for joining the Fitbit Community, it's great to have you on board. It's nice to see you around too @SteveH, thanks for all your help. 

@Fitnanaof3, as @SteveH, it's possible your old phone still has a Bluetooth connection with your Alta HR that's preventing the tracker from syncing with your new phone. If you still have your old phone around, please go to the Bluetooth settings on the phone and check if your tracker is on the list of paired devices. If it is, tap on it and select Forget this Device. Then, try to sync with your new phone. 

If your tracker is still not syncing correctly, please try the following:

• Make sure the latest version of the Fitbit app is installed on your phone.
• The software on your mobile device is up to date. To check, tap Settings > General > Software Update.
• Make sure there are no other Bluetooth devices around as they might interfere with the syncing process
• Check that your Fitbit device's battery isn't critically low.

If your device still won't sync, try these steps:

1. Force quit the Fitbit app. 
2. Go to Settings > Bluetooth and turn Bluetooth off and back on.
3. Open the Fitbit app.
4. If your Fitbit device didn't sync, restart your phone again.
5. Open the Fitbit app.
6. If your Fitbit device didn't sync, restart it one more time.
7. If your Fitbit device won't sync after the restart, log in to your Fitbit account on a different phone, tablet, or computer and try to sync.
8. If your Fitbit device still doesn’t sync, remove all other Fitbit devices from your account and from the list of connected Bluetooth devices on your mobile device and try to sync.

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