We are sorry to hear about your experience with your Samsung Galaxy phone having issues with fingerprint sensor not working, and we apologize for the inconvenience it caused you.
Submit an error report through Samsung Members app as follows:
Step 1. Long press Samsung Members icon on Apps screen and tap Error reports.
Step 2. Tap OK on agreement popup to send system log data.
Step 3. Select Symptom category "Sensor/Touch".
Step 4. Describe the problem in details and SEND.
Step 2. Press and hold the power and the volume down buttons at the same time to turn the device on.
Step 3. You will now be able to see Safe Mode on the bottom left-hand side of the screen.
Step 4. Try and check the fingerprint if its working.
For more help and assistance, you may contact us via our online Samsung Customer Care support channels below.