Hi,
Did you check the log on the server?
Reporting > logs
filter out the log with client and time then try to locate the user name.
Please check the directory sync as well. Please check the setting for Directory Synchronization Settings.
log into your PGP server and navigate to page as below
Consumers > Directory Synchronization > Settings
make sure you have a valid service account to reach the LDAP server.
verify it by test connection.