Hi,
Thank you for posting in Symantec community.
Could you confirm the SEP client version.
One of the password releates issue had been fixed in SEP 12.1 RU2 version.
Here are details:
Certain passwords cause irregular behavior with password security features
Fix ID: 2693672
Symptom: Certain passwords cause irregular behavior with password security features on the Symantec Endpoint Protection client.
Solution: Changed the way password string is verified to avoid a NULL value.