diff -urN ../z-push-2.6.4+0.orig/src/backend/searchldap/searchldap.php ./src/backend/searchldap/searchldap.php
--- ../z-push-2.6.4+0.orig/src/backend/searchldap/searchldap.php	2021-06-25 11:55:30.000000000 +0300
+++ ./src/backend/searchldap/searchldap.php	2023-09-26 19:47:17.329434000 +0300
@@ -121,6 +121,7 @@
 
         if (isset($this->connection) && $this->connection !== false) {
             $searchfilter = str_replace("SEARCHVALUE", $searchquery, LDAP_SEARCH_FILTER);
+            ZLog::Write(LOGLEVEL_DEBUG, sprintf("BackendSearchLDAP: Try apply search filter '%s'; search range: %s", $searchfilter, $searchrange));
             $result = @ldap_search($this->connection, LDAP_SEARCH_BASE, $searchfilter);
             if (!$result) {
                 ZLog::Write(LOGLEVEL_ERROR, "BackendSearchLDAP: Error in search query. Search aborted");
@@ -131,6 +132,7 @@
 
                 // TODO the limiting of the searchresults could be refactored into Utils as it's probably used more than once
                 $querycnt = $searchresult['count'];
+                ZLog::Write(LOGLEVEL_DEBUG, sprintf("BackendSearchLDAP: Result(s) found: %d", $querycnt));
                 //do not return more results as requested in range
                 $querylimit = (($rangeend + 1) < $querycnt) ? ($rangeend + 1) : $querycnt;
                 $items['range'] = $rangestart . '-' . ($querylimit-1);
@@ -158,6 +160,8 @@
             }
         }
 
+        ZLog::Write(LOGLEVEL_DEBUG, sprintf("BackendSearchLDAP: Items returned: %d", count($items) - 2));
+        ZLog::Write(LOGLEVEL_DEBUG, sprintf("BackendSearchLDAP: Items returned:\n%s", print_r($items, true)));
         return $items;
     }