Please check the Policy Server Trace log, it should suggest what is happening.
You may use the below smtracedefault.txt to copy into your smtracedefault.txt; then enable trace logging.
Snippet of C:\CA\siteminder\config\smtracedefault.txt
components: AgentFunc/Init, AgentFunc/UnInit, AgentFunc/IsProtected, AgentFunc/Login, AgentFunc/ChangePassword, AgentFunc/Validate, AgentFunc/Logout, AgentFunc/Authorize, Server/Policy_Server_General, IsProtected, Login_Logout, IsAuthorized, Tunnel_Service, JavaAPI, Directory_Access, ODBC/Sql_Statement_Begin_End, ODBC/Sql_Errors, ODBC/Connection_Monitor, LDAP/Ldap_Call_Begin_End, LDAP/Internal_Operation, LDAP/Ldap_Error_Messages, Fed_Server
data: Date, PreciseTime, SrcFile, Function, TransactionName, Message, Data, AgentName, Resource, User, Group, Realm, Domain, Directory, Policy, Rule, ActiveExpr, Expression, ErrorValue, ReturnValue, ErrorString, IPAddr, IPPort, Result, Returns, CallDetail, AuthScheme, AuthReason, AuthStatus, Query
version: 1.1
Regards
Hubert