Problem with i phone 6 bluetooth finding Fitbit

Hello,

I seem to have a problem with my I phone 6 Bluetooth connecting with my new Fitbit Blaze.

I am getting the following error message "The Operation couldn't be completed. (FBBluetoothErrorDomain error 3.)

For reference, I recently update the latest software on the phone and in addition I also have an I phone 6s as well for work and the Fitbit Blaze linked perfectly on the Bluetooth.

Please can someone assist?

Thanks,

Nigel