New Charge 3 unable to connect with Fitbit app

[hockysa]

Have an iphone 12 pro max previously using a charge 3 for a long time. 

screen died and ive replaced it with another charge 3 off amazon and the new one wont connect. 

Moderator Edit: Clarified subject

[hockysa]

Should note ive tried restarting bluetooth, restarting phone, restarting fitbit, clear user data on fitbit, reinstalled app. 

[FatimaFitbit]

Hi there @hockysa! It's great to see you here in the Fitbit Community!

Thank you so much for letting us know about this situation and for all your efforts.

Have you already checked if you can update the Fitbit app or if your Charge 3 has a firmware update pending?

I suggest you try to do this (even though you've already tried some of these troubleshooting steps the order is very important):

1. Turn off Bluetooth on your phone; wait 10 seconds, and then turn it back on.
2. Restart your Charge 3 or try a long restart: 
   1. Connect the device to the charging cable.
   2. Press and hold the button for 15 seconds while the device is connected to the charging cable.
   3. The device turns on and shows a battery symbol. Two vibrations occur: first a short one, then a medium one.
   4. The device turns off.
   5. The Charge 3 turns on and shows a progress bar and short vibrations occur. The progress bar completes. Note: There will be a total of 7 short vibrations.
   6. Remove the device from the charging cable. The device will shut down.
   7. Reconnect the device to the charging cable.
3. Turn your phone off and back on.
4. Remove your Fitbit device from the list of connected Bluetooth devices on your phone or tablet:
1. On your phone, tap Settings > Bluetooth.
2. Tap the information icon or gear icon next to the name of your Fitbit device.
3. Find the option to forget the device.
5. Try setting up your device again. How do I set up my Fitbit device?