Integrating services with LDAP is a good way to keep users/authentication centralised.
The tests below will return a users information, if not you’ll have some information to go off.
Test LDAP
ldapsearch -d 5 -D "CN=BINDUSER,OU=Users,DC=example,DC=company" -s sub -b "dc=example,dc=company" -h myldapserver -p 389 -w <PASSWORD> -x "(sAMAccountName=scott.daniels)"
Test LDAPs
ldapsearch -ZZ -d 5 -D "CN=BINDUSER,OU=Users,DC=example,DC=company" -s sub -b "dc=example,dc=company" -h myldapserver -p 636 -w <PASSWORD> -x "(sAMAccountName=scott.daniels)"