Why can't Ear (2) connect with the Nothing X app after reset?

If you are an iOS device user, please follow the steps below:
1. Open Settings in your iOS device, and select Bluetooth to confirm whether Ear (2) is in the list devices. If yes, please tap the "i" icon and select " Forget This Device"
2. Open the Nothing X app and follow the steps to connect to Ear (2) again.