JNDI Realm Configuration Review please

My Tomcat web application logs are telling me the user1 isn't in the specified mapped LDAP role/group coming from AD. I believe my issues lie with the JNDI Realm definition. Can someone review it please and see where I may be going wrong, I've included the DN information from AD as well:

My user1 account DN is

DistinguishedName : CN=user1,OU=Users,OU=Lab,DC=example,DC=com

The role/group Users I have specified in the web.xml config is

DistinguishedName : CN=Users,CN=Builtin,DC=example,DC=com

My Realm configuration is

<Realm
   className="org.apache.catalina.realm.JNDIRealm"
   debug="99"
   connectionURL="ldap://example.com:389"
   authentication="simple"
   referrals="follow"
   connectionName="cn=administrator,cn=users,dc=example,dc=com"
   connectionPassword="##########"
   userSearch="(sAMAccountName={0})"
   userBase="cn=users,dc=example,dc=com"
   userSubtree="true"
   userRoleName="memberOf"
   roleSearch="(member={0})"
   roleName="cn"
   roleSubtree="true"
   roleBase="cn=users,cn=builtin,dc=example,dc=com"/>