Do you feel that your Face Unlock and Fingerprint Unlock is responding very slow. I found out that it is due to Battery Optimization. So, Here are simple steps you may follow to increase it's speed by 2 times:
To try out ‘Biometric Unlock 2X Speed Booster,’ open Settings, go to Apps, tap the 3-dot menu button at the top and select Show system apps. Next, search for com.samsung.android.biometrics.app.settings and select it. Go to Battery » Optimize battery usage and make sure you have selected All apps from the drop-menu at the top. Search for com.samsung.android.biometrics.app.settings again and tap the toggle to disable this function. Reboot your phone to apply the changes. Just make sure you’ve waited until the phone fully rebooted and all the apps have loaded to determine if your sensor is or isn’t faster than before.
This will not harm your device nor it will need Rooting your device. It's very much simple. It will just turn off power saving for Biometric Unlock App.