diff --git a/CRM/Contact/BAO/Query.php b/CRM/Contact/BAO/Query.php
index 7952393fb8be..92c47c34bff0 100644
--- a/CRM/Contact/BAO/Query.php
+++ b/CRM/Contact/BAO/Query.php
@@ -4904,7 +4904,7 @@ public function searchQuery(
     //      MySQL expect the columns present in GROUP BY, must be present in SELECT clause and that results into error, needless to have other columns.
     //   2. When GROUP BY columns are present then disable FGB otherwise it demands to add ORDER BY columns in GROUP BY and eventually in SELECT
     //     clause. This will impact the search query output.
-    $disableFullGroupByMode = ($sortByChar || !empty($groupByCols));
+    $disableFullGroupByMode = ($sortByChar || !empty($groupByCols) || $groupContacts);
 
     if ($disableFullGroupByMode) {
       CRM_Core_DAO::disableFullGroupByMode();
@@ -4984,7 +4984,7 @@ public function getCachedContacts($cids, $includeContactIds) {
     $select .= sprintf(", (%s) AS _wgt", $this->createSqlCase('contact_a.id', $cids));
     $where .= sprintf(' AND contact_a.id IN (%s)', implode(',', $cids));
     $order = 'ORDER BY _wgt';
-    $groupBy = '';
+    $groupBy = $this->_useGroupBy ? ' GROUP BY contact_a.id' : '';
     $limit = '';
     $query = "$select $from $where $groupBy $order $limit";
 
diff --git a/CRM/Contact/Selector.php b/CRM/Contact/Selector.php
index 989716ddb440..12f73b41d112 100644
--- a/CRM/Contact/Selector.php
+++ b/CRM/Contact/Selector.php
@@ -1043,7 +1043,7 @@ public function fillupPrevNextCache($sort, $cacheKey, $start = 0, $end = self::C
 
     $selectSQL = "SELECT DISTINCT '$cacheKey', contact_a.id, contact_a.sort_name";
 
-    $sql = str_replace(array("SELECT contact_a.id as contact_id", "SELECT contact_a.id as id"), $selectSQL, $sql);
+    $sql = str_ireplace(array("SELECT contact_a.id as contact_id", "SELECT contact_a.id as id"), $selectSQL, $sql);
     try {
       Civi::service('prevnext')->fillWithSql($cacheKey, $sql);
     }