ProtectedDataAvailable returns false in device unlocked state

Our app relies on checking the availability of protected data to initiate Face ID authentication securely.   we are seeing UIApplication.shared.isProtectedDataAvailable returns false  for some users even the device has been unlocked state. 

 Due to unavailability of protected data significant users are experiencing problem in biometric prompting automatically. We are observing this issue across multiple iOS versions and device models. 

What are the common use cases (other than locked device state)to receive the UIApplication.shared.isProtectedDataAvailable -> false?

Are there are known issues with UIApplication.shared.isProtectedDataAvailable?

Any recommendation or workarounds to ensure the accuracy of protected data availability check?