Remove → Reset → Re-add
The issue may be caused by a temporary software glitch, but you can easily fix it by following these steps:
Remove the device from the app.
Reset the device by holding the reset button for 10 seconds.
The indicator light will start blinking red.
Re-add the device in the Smartlife app.
Go to device options
Select the doorbell in your Smartlife app from the main screen and tap the options in the top-right corner.
Remove the device
To remove the device, select the last option on the screen labeled "Remove device".
Reset the device
Hold the reset button for about five seconds. The device will reboot and start blinking. Make sure it blinks rapidly before proceeding.
Add the device again
From the main screen of the Smartlife app, tap the green plus to add a new device and follow the steps in the app.
Hopefully, this will solve the issue.