Not saving settings

Same issue for me, and it’s kicking me out every time I access a page.

Yeah, I saw the reason in the code. plugin tries to connect to something that is not configured yet!
I think I can provide code to get ahead

in ad-sso-user.php (around line 90)
After:
list($ad_sso_local_domain,, $ad_sso_local_userid) = $cred;

INSERT/UPDATE:

$ad_sso_fqdn = get_option('ad_sso_fqdn');

 if ( is_user_logged_in()) {
     global $current_user;
     get_currentuserinfo();
     $currentUserMatchesRemoteUser = (strtolower(trim($current_user->user_login)) === strtolower(trim($ad_sso_local_userid)));
     $settingsPresent = $ad_sso_fqdn && strlen($ad_sso_fqdn)!=0;
     if ( !$currentUserMatchesRemoteUser && $settingsPresent) {
         #wp_logout();
     }
 }

END INSERT

You may also want to update
@$bind = ldap_bind($connection, $ldapCred, $ad_sso_password);

to suppress initial connect warnings if needed