Fitbit Product Experts Alumni are retired members of the Fitbit Product Expert Program. Learn more
When you perform a factory reset the app will no longer recognize the unit and you have to re-link it with the app. Step 1 is to remove or unlink the unit from the app - go to the settings page, tap on the unit tile and then the trash icon on the upper right corner. Step 2 is to go to the phone's bluetooth settings and make sure the phone is not still linked to the unit - unlink it if it is. Step 3 is to go back to the app and then add the unit like you did when you first did it.
Warren | Cincinnati, OH
Versa Lite, Ionic, Charge3, Inspire HR, Blaze(retired), Alta( retired),- Pixel 3
Take a look at the Fitbit help site for further assistance and information.
Best Answer