Display chenged good display but figerprint not working.

The display of Samsung A50 is changed and the display is good but the fingerprint is not working.  When you place your finger, it says "couldn't register your fingerprint".  Why is that?

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0