are the users connecting to the correct Sign-in URL?
Check the configuration of SignIn URL ---> Realm ---> Authentication Servers (Mapped to your LDAP)
Do a policy trace for that user & realm and post the logs.
Refer this : https://docs.pulsesecure.net/WebHelp/Home.htm#PCS/PCS_AdminGuide_8.2/Using Policy Tracing.htm?Highlight=policy trace
Thanks,
Ray.

Pulse Connect Secure Certified Expert